SOLID BITUMENS 



THEIR 



Physical and Chemical Properties 

AND 

Chemical Analysis 



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THE MYRON C. CLARK PUBLISHING CO. 

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SOLID BITUMENS 



THEIR 



Physical and Chemical Properties 



AND 



Chemical Analysis 



TOGETHER WITH 



A Treatise on the Chemical Technology 



OF 



Bituminous Pavements 



BY 

S. F. PECKHAM, A. M. 

'I CHEMIST 

to the 
Department of Finance, City of New York 

Member of the 

American Philosophical Society; the Society of Chemical Industry! The 

American Chemical Society; The American Institute of 

Chemical Engineers, Etc. 



NEW YORK AND CHICAGO 
THE MYRON C. CLARK PUBLISHING CO, 

LONDON 

E. & F. N. SPON, LTD., 57 Haymarket 
1909 



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COPYRIGHT 1009 

BY 
THE MYRON C. CLARK PUBLISHING Co 



Minincd.pt 



PREFACE. 

This book has been written at the request of several 
friends. I began experimenting on bitumens while a student 
in Brown University in 1859. Interrupted by the Civil War, I 
again took up the work on the Pacific Coast in 1865 and it has 
been prosecuted almost continually until the present time, a 
period of forty years. Happy in the personal friendship of C. 
M. Warren, in whose laboratory I spent several months, I have 
used nearly every method of investigation that has been pro- 
posed in the United States and Europe, and have read nearly 
everything that has been published relating to bitumens from 
Boussingault's Memoir to the present time. It would be 
strange, if, with such experience, I had not learned much that 
might be useful to my fellow men. This is my apology for 
offering a work on solid Bitumens. 

The word Asphalt has become so hackneyed through mis- 
use, that I have avoided its use wherever possible. 

While the work represents much of personal experience, 
my aim has been to offer everything of value relating to the 
subject, giving full justice to all, whether they agree with me 
or not. If anything essential has been omitted, it is done 
through inadvertence, without intention. So far as has been 
possible, reference has been made to original memoirs. I am 
aware that there may be instances in which I have not met 
the originals, in which case the wrong reference is accidental. 

With these few words of explanation and apology, I dedi- 
cate my work to my fellow laborers in a field of vast extent 
and intricate paths, the boundaries of which no man living will 
discover. S. F. P. 

New York, October i, 1909. 



CONTENTS. 
PART I. THE NATURAL HISTORY OF BITUMENS. 

Page. 
INTRODUCTION x 

CHAPTER I. GEOGRAPHICAL DISTRIBUTION OF BITU- 
MENS 7 

CHAPTER II. ORIGIN OF BITUMENS 

Geological Occurrence of Bitumens 21 

CHAPTER HI. THE CLASSIFICATION OF BITUMINOUS 

SUBSTANCES 62 

CHAPTER IV. THE DERIVATION OF NATURAL SOLID 

BITUMENS : 82 

Evaporation 82 

Decomposition 82 

Polymerization 83 

CHAPTER V. THE DERIVATION OF BITUMINOUS ROCKS. 85 
CHAPTER VI. THE DERIVATION OF ARTIFICIAL SOLID 

BITUMENS 87 

PART II. THE CHEMISTRY OF BITUMENS. 

CHAPTER VII. GENERAL CONSIDERATIONS CONCERNING 

THE CHEMISTRY OF SOLID BITUMENS 90 

CHAPTER VIII. BOUSSINGAULT'S MEMOIR UPON THE 

COMPOSITION OF BITUMENS 91 

CHAPTER IX. THE USE OF THE WORDS, PETROLENE, 

ASPHALTENE, ETC 98 

CHAPTER X. THE ULTIMATE ANALYSIS OF SOLID BITU- 
MENS 107 

Carbon and Hydrogen 107 

Oxygen 107 

Sulphur 108 

Warren's Method 109 

E. H. Hodgson's Method 110 

S. F. and H. E. Peckham's Methods 112 

S. S. Sadtler's Method 114 

Garrett and Lomax's Method 117 

C. F. Mabery's Method 118, 122 

Lidow's Method 118 

Eschka's Method 118 

v 



vi CONTENTS. 

Page. 

Henrique's "Method 118 

v. Konek's Method 120, 122 

Engler's Method 123 

Nitrogen : 

Soda Lime Process 125 

Mabery's Process 125 

Test for Basic Oils 127 

CHAPTER XI. THE PROXIMATE ANALYSIS OE SOLID 

BITUMENS 129 

Peckham's Retort 130 

Parianite or Trinidad Pitch 132 

The Gas 132 

The Lake Water , 133 

Aqueous Solution of the Pitch 134 

The Alkaline Solution 135 

The Determination of Water 137 

The Petroleum Ether Solution 137 

The Turpentine Solution 138 

The Chloroform Soluble 138 

The Hydrochloric Acid Solution 139 

The Residue 139 

The Organic Matter Not Bitumen 140 

The Mineral Matter 141 

CHAPTER XII. THE TECHNICAL ANALYSIS OF SOLID 

BITUMENS 148 

Introduction 148 

Methods of Distillation 149 

Methods of Solution 149 

Torrey's Method 150 

Sadtler's Method 151 

Acetone 152 

Holde's Method 153 

Engler's Method 154 

Miss Linton's Method 155 

A. W. Dow's Method 171 

Bitumen Soluble in Carbon Bisulphide 173 

Bitumen Soluble in Naphtha 175 

Clifford Richardson's Method 177 

Determination of Total Bitumen 177 

Mineral ' Matter or Ash 179 

Organic Matter Insoluble 179 

Naphtha Soluble Bitumen 179 

Determination of Character of the Malthenes 181 

Determination of Bitumen Soluble in Carbon Tetrachloride 182 

Peckham's Aoparatus for Determination of Solid Bitumens 186 

Peckham's Method . 190 



CONTENTS. vii 

Page. 

CHAPTER XIII. SPECIAL CHEMICAL AND PHYSICAL 
METHODS OF ANALYSIS BY WHICH SOLID BITU- 
MENS MAY BE RECOGNIZED AND DISTINGUISHED. . .196 

Fixed Carbon 196 

Street Mixtures and Surfaces 197 

Fuming Sulphuric Acid Test 198 

Alcohol and Alcohol-Benzine Tests 200 

Precipitation Method 201 

Determination of Paraffine 202 

Artificial Asphalts 204 

Distinguishing Between Artificial Asphalts 205 

Microscope .206 

Spectroscope 207 

CHAPTER XIV. MISCELLANEOUS METHODS APPLIED TO 
STREET MIXTURES AND SURFACES, BITUMINOUS 
PAVING BLOCKS, BITUMINOUS CONCRETE, WOOD 
PAVING BLOCKS, CEMENTS, CEMENT MORTARS AND 

CONCRETE, ETC 212 

The Sample 212 

Asphalt Paving Blocks 213 

Wood Paving Blocks 214 

Examination of Creosote Oil 215 

Retort and Graphite Hood 216 

A Method for a Correlation of the Chemical and Physical Exam- 
ination of Cements, Cement Mortars and Concretes 217 

Scheme of Prof. Henry Carmichael 219 

Scheme of R. L. Humphrey. . .220 

Dr. Hillebrand's Conclusions : 222 

Dr. Hillebrand's Suggestions 223 

Mr. Clifford Richardson's Scheme for Analysis.... 225 

Mr. Bertram Blount's Critique 229 

Scheme of Com. of Lehigh Valley Section of Am. Chem. Society. .232 

Correspondence 236 

Newberry's Formula 241 

S. F. Peckham's Method of Analysis 244 

(1) Volatile at a Red Heat. ...:......... 245 

(2) The Sample 245 

(3) The Solution 245 

(4) The Residue 249 

(5) Silica 250 

(6) Alumina and Ferric Oxide 251 

(7) Lime 252 



.252 



(8) Magnesia 

(9) Sulphuric Oxide 253 

(10) Alkalies 253 

(11) Carbon Dioxide 253 



Mil 

Page. 

Neat Cements 255 

Mortars 256 

Concretes 257 

PART III. THE PHYSICAL PROPERTIES OF SOLID 

BITUMENS. 

CHAPTER XV. SPECIFIC GRAVITY, ETC 262 

Specific Gravity 262 

Softening Point 262 

Mabery and Sieplein 262 

J. Kovacs 264 

J. G. Holmes 267 

The Method With Cylinders 269 

Muck's Pitch Stick Method 268 

Buchanan's Method 268 

Method With Bent Tubes 268 

Test Tube and Cone Method 269 

Straight Tube Method 271 

"Aktien Gesellschaft f. Teer-u.-Erdolindustrie" Method 271 

Flow 274 

Ductility 274 

Dow's Apparatus for Ductility 275 

Penetration 275 

Dow's Apparatus for Penetration 277 

PART IV. CHEMICAL TECHNOLOGY OF BITUMI- 
NOUS STREETS. 

CHAPTER XVI. HISTORICAL INTRODUCTION 281 

"Asphalt Streets" 286 

CHAPTER XVII. A MODERN STREET 290 

The Foundation 290 

Surfaces 295 

CHAPTER XVIII. BITULITHIC STREETS 301 

CHAPTER XIX. THE OILED ROADS AND STREETS OF THE 

PACIFIC COAST 304 

CHAPTER XX. ASPHALT BLOCKS 310 

Table of Dimension of Crushed Stone 310 

CHAPTER XXL WOOD BLOCKS 313 

CHAPTER XXII. CONCLUSIONS 315 

INDEX OF SUBJECTS 319 

INDEX OF NAMES.. ..323 



PART I. 

THE NATURAL HISTORY OF 
BITUMENS. 



INTRODUCTION. 

The exact meaning of the word "bitumen" has in 
recent years become involved in some obscurity. In antiquity, 
and, indeed, until a recent date, it had a definite meaning. 
For instance, in Genesis xi, 3, a Hebrew word occurs which 
designates the cementing substance used in constructing the 
walls of the tower of Babel. In the Septuagint this word is 
translated asphaltos, and in the Vulgate bitumen. In the 
Bishops' Bible of 1568, and in subsequent translations into 
English; the word is rendered "slime." In the Douay transla- 
tion of 1600 it is "bi'tume." In the Protestant French trans- 
lation it is "bittime." In Luther's German Bible it is "thon," 
the German word for clay. In removing the magnificent ala- 
baster slabs that were used to adorn the palaces of Ninevah 
and Babylon, it has been discoverd that the material used to 
cement and hold the slabs in position, was mineral pitch, 
softened by heat. 

The word "asphaltum" is said to be derived from a, privi- 
tive and ^a\x<r > "I cause to slip." It therefore signifies 
a substance that prevents one from slipping, and it was ap- 
plied to the solid forms of bitumen that soften in the sun. 
This substance was not rare in so-called Bible lands, embrac- 
ing the valley of the Tigris and Euphrates, the tablelands of 
Mesopotamia and the valley of the Jordan. It was of fre- 
quent occurrence along the shores 'of the Dead Sea, and was 
gathered and sold in the caravan trade that passed through 
the land of Moab and Petrea into Egypt, where it was sold 
for the linings of silos and cisterns and for use in embalming 
the dead. Cisterns and silos are still intact that were built in 
Petrea and Egypt, and lined with asphaltum from two' to 
three thousand years ago, yet the manner of their construc- 
tion and the locality from which the bitumen was obtained, 
and even by whom they were built, is at present unknown. 

During the Middle Ages, asphaltum and other forms of 
bitumen appear to have found but few uses, and they are sel- 

I 



2 SOLID BITi'MEXS. 

dom mentioned. The words bitumen, asphaltum, petroleum 
and naphtha appear to have been used with different mean- 
ings, and also interchangeably or synonymously ; yet the 
words were generally used to signify a thing that was located 
and defined by further description, so that the bitumen of the 
Dead Sea was recognized as asphaltum, or solid bitumen ; that 
of Zante as petroleum, etc. 

It is only within the nineteenth century that any serious 
confusion in nomenclature has appeared, and then the trouble 
has arisen almost wholly from commercial considerations. 
About the year 1830, the French schist oil began to assume 
importance. Later, the Scotch paraffine industry arose, and 
during the decade from 1850 to 1860 extended from Scotland 
to the United States, into which both the material used and 
the methods of manufacture were imported. In France the 
materials used were properly called "the bituminous shales 
of Autun." In Scotland the material was called ''boghead 
coal," "boghead shale" and "boghead mineral ;" it was also 
called torbanite. The expense attending the importation of 
the boghead shale into the United States, led the Downer 
Kerosene Oil Co., of Boston, Mass., and Portland, Me., to 
make an exclusive contract for the Albertite of New Bruns- 
wick. It was called Albert Coal, asphalt, pitch, etc. ; and, for 
commercial reasons, became the subject of a very important 
law r suit, in which, as experts, scientific men gave very conflict- 
ing testimony, one party claiming that the material was as- 
phaltum, and the other that it was coal. It was finally decid- 
ed that the material was not coal and did not belong ;o the 
crown.* This decision established the fact, both in law and 
science, that asphaltum is not coal. 

In line with this decision, the late Dr. T. Sterry Hunt, 
as long ago as i863,t separated pyrobituminous from bitumin- 
ous minerals. The fundamental principle underlying the use 
of this word "pyrobituminous," exists in the fact, that schists, 
shales and all crude coals, except anthracite, together with 
many other substances, wholly or in part of organic origin, 

*Taylor's "Statistics of Coal," Philadelphia, 1855, p. 516. Taylor's depo- 
sition before the Supreme Court at Halifax, N. S., respecting the asphaltum 
mine at Hillsborough, Philadelphia, 1851. On a New Varietv of Asphalt 
C. M. Wetherell. Trans. Am. Philos. Society (N. S.), 10, 353. " 

tAm. Jour, of Science (2) 35 p. 157. Chemical and Geological Essays. 
J. R. Osgood & Co., Boston, 1875. 



yield products that resemble bitumens on being heated to 
destructive distillation. Why this clearly scientific, and very 
convenient distinction has not been made the foundation upon 
which all scientific definitions relating to bitumens proceed, 
is difficult to explain. Yet, until this distinction is fully rec- 
ognized, writers will continue to mix up bituminous coals, 
schists of Autun and Mansfield, boghead mineral, etc., with 
all sorts of bitumens to the infinite confusion of the discus- 
sion of bitumens. These coals, schists and shales, while 
containing a large amount of organic matter, are nearly as 
insoluble in the solvents of bitumen, viz. : ethyl ether, chlor- 
oform, benzole, etc., as they are in distilled water ; hence Dr. 
Hunt made the action of these solvents exclusive of the two 
classes of substances. All true bitumens are miscible with, 
or almost wholly soluble in chloroform, a test that clearly 
separates them from pyrobituminous minerals. So-called 
-"asphaltic coals" are not coals at all, but are simply geologi- 
cally old asphaltums. 

The word bitumen therefore is a generic term that in- 
cludes a large number of substances that are brought together 
by reason of possessing certain physical properties in com- 
mon. Under this generic term the species are not yet clearly 
defined. The words, natural gas, naphtha, petroleum, maltha, 
asphaltum and asphalt, are not names of things having a 
constant and well recognized chemical composition. When 
a true system of nomenclature shall have been adopted, under 
which the species and subspecies under bitumen shall receive 
appropriate names, it will be found that a species may occur 
in nature in any or all of the several conditions, from natural 
gas to asphaltum. A true system, therefore, must name and 
classify the bitumens themselves. 

In any attempt to define bitumen, it is at once apparent 
that there are a large number of minerals, consisting in part 
of bitumen that are, strictly speaking, rocks. To this class of 
substances belong the Seyssel limestone and sandstone of the 
upper valley of the Rhone, the Limmer and Ragusa rocks, 
the Niagara limestone of Chicago, the bituminous limestones 
and sandstones of Utah and Oklahoma, the Turrell- 
ite of Texas, the sandstones of Kentucky, the Athabasca 



4 SOLID BITUMENS. 

River and California. These occur in beds of sedimentary or 
crystalline rock, often of immense extent and thickness, im- 
pregnated with bitumen of varying consistency and quality. 
Sometimes, the bitumen is found to be quite fluid after it is 
separated from the rock, but it is never solid. In some in- 
stances it may become solid, by exposure to atmospheric influ- 
ences, and in others not. Mr. Malo and other French writers 
have called these rocks "asphalte." They have also called 
asphaltum by the same name, as if the things were identical 
and the words synonymous. German authors have generally 
used the French word. Among English speaking peoples 
great confusion has followed an attempt to use the French 
word, as the most unlike things are called "asphalt." The 
author suggested using the word asphalte to designate only 
the different bituminous rocks, but in a late letter, Prof. 
George Lunge informs me that the French and German lan- 
guages present (difficulties, wellnigh insurmountable when 
such an attempt is made. 

The so-called Trinidad pitch, as it is found in and around 
the lake, is a unique mixture of bitumen, with mineral and 
vegetable matter, which is inflated with gas. When removed 
from the deposit, the water rapidly dries out, the gas escapes, 
the mass becomes brittle and changes from a brown to a blue- 
black color, acquiring a sticky consistency as it loses water. 
If the dried mass is put into water, the water is reabsorbed 
and the mass again becomes brown. At a rough estimate, less 
than 25 per cent of the natural cheese pitch that fills the lake 
is bitumen. Trinidad pitch is only in part bitumen and is a 
complex mineral species, for which the author has elsewhere 
suggested the name "Parianite," from the formation in which 
the celebrated lake occurs.* 

From the earliest mention of the substance in Greek and 
Roman literature, to within what is termed the modern period, 
the typical asphaltum of commerce has been the solid bitumen 
found on the shores of the Dead Sea. In later years, as the 
knowledge of mankind has extended, not only respecting the 
surface and extent of the surface of the earth, but also re- 
specting the things found in and upon that surface, the word 



"Journal of the Franklin Institute, Nov., 1895. 



INTRODUCTION. 

j 

asphalt has been used to designate a number of substances 
that may be arranged in a series, the members of which differ 
but slightly in those closely related, but very widely in the 
extremes. The confusion arising from this cause has been 'of 
slow growth, and has led to inconvenience only within com- 
paratively recent years. 

In the English translation of Boerhaave's Chemistry 
published in London in 1732, which was a classic in its time, 
asphaltum, with other forms of bitumen, is classed as a vari- 
ety of sulphur. At present these substances are no longer 
associated, but a great lack of clearness has arisen from the 
inability of many writers to appreciate the differences that 
exist between substances with which they are locally familiar, 
and other similar, but in many respects quite different mate- 
rials found in other localities. There is, too, a disposition to 
name any solid mineral containing bitumen, asphaltum or 
asphalt, without regard to either the kind or amount of im- 
purities with which the bitumen is associated. Another source 
of confusion is found in the fact that for various reasons those 
substances more or less closely allied to the natural solid 
bitumens that are by-products of many technical processes, 
have been named and described as asphaltum gr asphalt. 
These substances are often not bitumen at all. 

Still another source of confusion is the use of the word 
pitch as an equivalent for asphaltum. This~ word comes down 
through all modern languages from an unknown antiquity and 
has been used with its equivalent to designate the tarry or 
resinous residuum obtained by boiling down or distilling the 
turpentine of coniferous trees. It is a vegetable substance 
originality. The term mineral pitch has been applied to the 
purer forms of asphaltum that resemble in appearance the 
black pitch of the apothecaries. The Germans also use the 
term "glance pitch" to designate those very pure and hard 
varieties of asphaltum that break with a brilliant, glistening 
fracture, resembling obsidian more nearly than the less pure 
varieties of asphalt. This use of the word pitch, specialized 
as mineral pitch, as equivalent to asphaltum, while having 
little to recommend it, was not particularly objectionable until 
it became gradually applied to a great variety of substances, 
many of which are the same by-products of manufacture al- 



fueled to above. These artificial by-products have also been 
called artificial asphaltums and asphalts, and in some in- 
stances artificial bitumens. They are solid residuums obtained 
from the distillation, usually destructive, of coal tar, blast- 
furnace tar, coke oven tar, candle tar, California petroleum, 
maltha, etc.* 

Reference has already been made to the distinction made 
by Dr. Hunt between coals and bitumens by the use of sol- 
vents. The natural bitumens are not as readily to be dis- 
tinguished as pyrobitumens from the pitches or artificial bitu- 
mens so-called, as the latter are miscible with nearly equal fa- 
cility in nearly all the menstrua that dissolve natural 
bitumens. They are, however, more easily to be distinguished 
by chemical tests and are in no manner equivalent to each 
other. The artificial bitumens, so-called, possess far less 
chemical stability in the atmosphere than natural bitumens. 
Mr. Clifford Richardson has very happily chosen the name 
"residual pitch'' to designate these products of destructive dis- 
tillation. 

The word bitumen may, therefore, be strictly defined as 
a generic term that is used to designate a class of minerals 
as they occur in nature, that are soluble in chloroform and 
other neutral liquids. They all consist principally of com- 
pounds of carbon and hydrogen, but often contain compounds 
of nitrogen, sulphur and oxygen, and in the solid forms, com- 
pounds of iron and alumina. The species under bitumen oc- 
cur in the gaseous, liquid and solid states and in mixture with 
solid minerals to form rocks. 

This work is devoted to a discussion of the solid forms 
of bitumen and their uses in the construction of pavements. 

Paving & Municipal Engineering, 1894, v o i. vii, p. 310. 



CHAPTER I. 

THE GEOGRAPHICAL DISTRIBUTION OF SOLID 

AND SEMI-SOLID BITUMENS AND 

BITUMINOUS ROCKS. 

In the valley of the Connecticut River solid bitumens 
have been observed filling thin seams and veins in eruptive 
rocks.* 

In the eastern portion of the state of New York, in the 
region of eruptive and metamorphic rocks, veins occur similar 
to those reported from Connecticut. f In some of the cavities 
of the New York limestones the crystals which line them are 
covered with a substance, black and shining, with the frac- 
ture and appearance of anthracite. 

Veins occur in the trap of New Jersey filled with a bitu- 
minous mineral. J 

In Ritchie county, West Virginia, on McFarland's Run, 
a small tributary of the south fork of Hughes River, which 
enters the Little Kanawha, is found a vein of bituminous 
material, called asphaltum, and named Grahamite, which is 
no doubt closely related to other forms of bitumen, but in 
precisely what manner, has been a subject of much contro- 
versy. The vein cuts the nearly horizontal sandstone strata 
nearly at right angles and 'stands vertical to the horizon. 
Very extensive mining operations were commenced upon the 
vein, but the mass was soon worked down to the lower level 
of the sandstones, and was found to pinch out in the shales 
beneath. It presented all of the phenomena of an eruptive 
mass. The material was found to be very valuable for enrich- 
ing illuminating gas, for which it was chiefly used ; but a 
thickness of several hundred feet of shale, in which it was 
almost entirely wanting, prevented continuous working, and 
the mine has long been abandoned. Other smaller but other- 

*J. C. Percival on "Indurated Bitumen." Geol. of Conn., Am. Jour. Sci- 
ence (3), xvi, 130. 

tL. C. Beck, Am. Jour. Science (1) xlv, 335. 
JI. C. Russell, Am. Jour. Science (3). xvi, 112. 



8 

wise similar veins occur in the neighborhood. From a visit 
made to the Grahamite deposit in 1881 and a very careful 
examination of the locality in company with several of the 
men who helped mine out the deposit, the author concludes, 
after several hours' conversation with these men, that the 
only description of the occurrence of Grahamite that conforms 
to the observed facts is found in the report of Prof. Henry 
Wurtz, published in 1865. His observations were made while 
the mine was being operated. He says : "The general aspect 
of the mass, as well as all the results of a minute examina- 
tion of the accompanying phenomena, lead irresistibly to the 
conclusion that we have here a fissure which has been filled 
by an exudation, in a pasty condition, of a resinoid substance 
derived from or formed by some metamorphosis of unknown 
fossil matter contained in deepseated strata intersected by the 
fissure or dike. It is not necessary to suppose a degree of 
fluidity greater, than semifused pitch or inspissated tar. Such 
a soft doughy mass, though flowing but slowly, would in time 
be forced by a very moderate pressure into every portion and 
into every crevice of the fissure."* 

In Texas, near the mouth of the Brazos River, and in 
other parts of Texas, beds of asphaltum occur, evidently re- 
sulting from the decomposition of maltha or petroleum. 

In Montague County, on the south side of the Red River 
Valley, deposits are found of sand saturated with bitumen. 
While the mineral is, geolQgically speaking, a rock, the sand 
falls asunder when the bitumen is dissolved away from it. 
While the deposits are of considerable extent, they are not 
easily accessible and are only of local value. 

A deposit of limestone impregnated with bitumen, of 
limited extent, occurs near the town of Burnet, Burnet Coun- 
ty, Texas. 

The most valuable deposits of solid bitumen in Texas are 
situated in Uvalde County. "The only deposit worked in 
this somewhat extensive field is that by the Uvalde Asphalt 
Co., 18 miles west of Uvalde and 8 miles southeast of Cline, a 



*J. P. Lesley, Proc. Am. Philos. Soc., March 20. 1863; Report on a Min- 
eral Formation in West Virginia, Henry Wurtz, 1895; Proc. Am. Assoc. Adv. 
Sci., xviii, 124. 1869; S. F. Peckham, Am. Jour. Sci (2), xlviii, 362, 1869, 
and Am. G. L. Jour., xi, 164; W. M. Fontaine, Am. Jour. Sci. (3), vi. 1873; 
I. C. White, Bui. Geo. Soc. Am. x, 1898; Asphalt and Bituminous Rock De- 
posits of the United States, G. H. Eldridge, 1901, p. 232. 



GEOGRAPHICAL DISTRIBUTION. 9 

station on the Southern Pacific railroad, with which it is con- 
nected by rail. The material is a coquina, or shell limestone, 
saturated with bitumen into a solid mass. When the bitumen 
is dissolved with chloroform, the shells remain, connected to- 
gether at their points of contact and containing in the cavities 
of the shells crystalline masses of rhomb spar and pyrite. I 
have examined a number of specimens from this locality and 
they are very nearly identical in their characteristics and very 
unlike any similar material that I have seen. Several other 
deposits in the vicinity, of similar material, but less accessible, 
have been discovered. 

The bitumen itself has a brilliant lustre when fractured, 
but where, in the broken rock, that portion which formerly 
was in contact with the walls of the cavity it filled, is exposed, 
the brilliant lustre is wanting, a surface of dead black re- 
placing it. The bitumen, when extracted, is hard and brittle 
and at the same time flexible. In hardening in the rock it 
apparently suffered no shrinkage. The asphaltic limestone it- 
self is tough and unyielding. 

Bitumen occurs in a vein in the region of Upper Willow 
Creek, in the Middle Park, Colorado. The material resembles 
Gilsonite and has been injected into a fissure vein. 

In that portion of Utah adjoining the northwestern por- 
tion of Colorado, solid bitumens occur in great variety. Vari- 
ous names, as Wurtzilite, nigrite, etc., have been given to these 
varieties. The bitumens of commercial importance are those 
known as ozocerite, Gilsonite and bituminous sandstones. 
They are found in what is known as the Uintah basin, in 
which lies the valley of the Green River, and the streams that 
unite to form it. Gilsonite is a black solid of very brilliant 
luster and with a conchoidal fracture, and exceedingly brittle. 
When pulverized it forms a chocolate-brown powder. In the 
vein it exhibits the "pencillate structure that is observed in 
starch and other substances under pressure. It occurs over 
an area that extends about five miles east of the Colorado line 
westward for sixty miles into Utah." 

"The larger veins are somewhat scattered, one lying about 
3 T /^ miles due east of Fort Duchesne, a second in the region of 
Upper Evacuation Creek, and the two or three others of chief 
importance, in the vicinity of White River and the Colorado- 



I0 SOLID BITi'MEXS. 

Utah line. Besides these, there is a 14-in. vein near the west- 
ern edge of the area in the vicinity of the fortieth parallel ; 
another of equal size about six miles southeast of the junc- 
tion of the Green and White Rivers ; a third in a gulch four 
or five miles northwest of Ouray Agency, west of the 
Duchesne River, and a number from 1/16 in. to one ft. in 
thickness in an area about ten miles wide, extending from 
Willow Creek eastward for twenty-five miles along the sides 
of the Green and White Rivers. The vein near Fort Duchesne 
has been worked longest, and has been opened to a depth of 
over 100 ft. 

The most important locality of Gilsonite is the region im- 
mediately north of W T hite River, near the eastern edge of 
Utah. Here are three nearly parallel vertical veins of almost 
constant N. 60 W. trend, cutting and extending slightly into 
the shales of the Green River below. The veins are known 
as the East and West Bonanzas and the Cowboy, the two 
Bonanzas uniting to the southeast. The two Bonanzas are 
at varying distance from each other, while from the East 
Bonanza the Cowboy is distant about 2j/ 2 miles. None of the 
veins were exploited, as recently as 1901, only a shallow pros- 
pect appearing here and there. In general features and in 
filling they are like the veins near Fort Duchesne and the 
material occupying them is unquestionably derived from the 
same ultimate source as that in the others. The Bonanza 
veins may be traced from the White River canon northwest- 
ward for 7 miles. The Cowboy is the largest of the White 
River veins. Its maximum width is 18 ft., but it holds a width 
of 8 to 12 ft. for a distance of 3 or 4 miles and at least 4 ft. 
for nearly 6 miles. The total length is between 7 and 8 miles. 
These veins, like those of West Virginia, are characterized 
by containing "horses" or pieces of wall rock embedded in the 
asphaltic mass, showing that the mass was eruptive, semi- 
solid and plastic, not fluid, when it was forced into the fis- 
sure.* 

Veins of Wurtzilite, nigrite, ozocerite and also beds of 

*The Asphalt and Bituminous Rock Deposits of the United States by 
George H. Eldridge, p. 340-350. S. F. Peckham, Am. Jour. Sci. (2), xiviii, 
362, ^OV., 1869. 



GEOGRAPHICAL DISTRIBUTION. II 

bituminous limestones and sandstones occur in the valleys 
of the Green and White Rivers in northeastern Utah. 

Next in commercial importance to the deposits of Utah 
are those of Kentucky. They occur as sandstones impreg- 
nated with bitumen. They extend from near Garfield in 
Breckinridge County through Grayson, Edmonson and War- 
ren counties to Russellville in Logan County. Another de- 
posit is found in the northeastern part of the state in Rowan 
county. The sandstones are very hard and are reduced to a 
powder with difficulty. These sandstones have been exploit- 
ed commercially to a limited extent, the stone having been 
crushed and used in street paving in Columbus, O., Buffalo, 
N. Y., and other cities. Bituminous sandstones also occur in 
eastern Kentucky, in Carter county. The deposits have not 
been proved commercially valuable. 

There is a deposit of bituminous sandstone near Higgins- 
ville, Lafayette county, Mo. It has not yet been proved of 
commercial value.* 

There are very extensive deposits of bituminous lime- 
stones and sands in the Chickasaw nation of Oklahoma, 
both east and west of the Washita River. The eastern 
deposits are mainly in or near the valley of Rock Creek, east 
of Dougherty, a station on the Gulf, Colorado & Santa Fe 
railroad. These deposits have been exploited by the Gilsonite 
Paving & Roofing Co. of St. Louis, and ~by others. On the 
west, the deposits are found in the prairies that border the 
southern and western slopes of the Arbuckle mountains. 
Large maltha springs and beds of impure asphaltum occur to 
the south and southwest of the town of Elk. The principal 
deposits that have been worked are near the village of Wood- 
ford w r here the Schneider Bros, and the Smiths made several 
openings in a deposit of bituminous sand that formed a sharp 
anticlinal arch extending across the country for several miles. 
The material is sand, held together by bitumen which is readi : 
ly separated by boiling water. The bitumen, when separated, 
is a semisolid maltha of great tenacity and purity. In this 
neighborhood other deposits of minor importance occur, but 
they have not been worked on a commercial scale. In the 

*Asphalt and Bituminous Rock Deposits of the United States, by Geo. 
H. Eldridge, p. 240-262. 



I2 SOLID BITUMEXS. 

center of the Choctaw nation, on the headwaters of Tenmile 
Creek, in the Impson valley, occurs the vein of bitumen re- 
sembling Albertite that is called Impsonite. It has not yet 
been made of commercial importance.* At Velma, Stephens 
Co., and near Springer, Carter Co., a very pure form of asphal- 
tum has been found, and called Grahamite, but its resemblance 
to Grahamite is quite remote. 

The deposits of asphaltum and bituminous sandstones of 
California are found in the immediate region of the Coast 
Range, and are distributed from Point Arena in the north to 
Los Angeles in the south. They occur on the east and west 
slope of the general range and at several points within. As at 
present known, they are confined chiefly to that portion of the 
range lying south of the Bay of San Francisco. The purer 
variety of asphaltum occurs in the vicinity of McKittrick in 
Kern county, at the eastern base of the mountains near Santa 
Maria, in the Grasiosa and Azufre Hills, and again six or 
seven miles west of Santa Barbara on the coast. Bituminous 
sandstones occur at Point Arena, on the north, and at several 
localities in the south, notably near Santa Crux, San Luis 
Obispo, Los Alamos and Carpinteria. 

The Santa Crux district of bituminous sandstone lies 
about sixty miles south of San Francisco. The deposits occur 
from five to six miles northwest of the city of Santa Crux, the 
more remote being the most extensively quarried. The prop- 
erties are controlled by a number of private individuals and 
by the City Street Improvement Co. of San Francisco. Most 
of the quarries are opened near the summit of the Empire 
Ridge, which parallels the sea and which is a spur of the 
Santa Crux mountains. The quarries of the City Street Im- 
provement Co. are opened at two different horizons, several 
of the quarries having their floors about 100 ft. above those 
of the others. These bituminous sandstones are essentially 
an aggregate of minute to medium sized quartz grains, which 
in form are sub-angular to rounded. It is in the interstices of 
this rock that the bitumen is held to an extent of from 14 to 
16 per cent of the average specimen. The rock varies, but 
on the whole is soft, crumbling in the sun, very tenaceous and 

*Asphalt and Bituminous Rock Deposits of the United States, by Geo. 
H. Eldridge, pp. 262-320. 



GEOGRAPHICAL DISTIUBVT1OX. 13 

gummy to the touch. The color is black to brownish-black, 
weathering to gray on exposure to the atmosphere. The tem- 
perature of the atmosphere, according as it is cold or hot, ren- 
ders the rock either brittle or soft. 

These deposits are extensively quarried for use on the 
streets of San Francisco and other cities of the Pacific coast.* 

Bituminous sandstone is scattered along the length of the 
Salinas valley and its tributaries for a distance of 50 miles 
midway of its length. The localities best known are reached 
from Metz, King City, San Ardo and Bradley.f 

The San Luis Obispo district of bitumen bearing rocks 
embraces an area of about 80 square miles, south and south- 
west of the town of San Luis Obispo ; it is coincident with the 
ridge of moderate height that separates the San Luis valley 
from the sea, and which is the southeastern end of the San 
Luis Range. The quarries of the region are chiefly distributed 
about the periphery of the San Pablo terrace, but not a few 
have been opened well within its border. Unopened deposits 
are exposed at many localiti >s throughout the area. Some 
localities show barren rock alone, others a bed with only 
traces of bitumen; still others a rock enriched sufficiently to 
afford a product of first grade. Many of the quarries, how- 
ever, rme been long abandoned, and it is impossible to judge 
unerringly of their actual contents. 

The quarries of the San Luis Obispo region embrace a 
score or more of openings of various sizes, many of which 
have long been idle. The rock itself is fine graiii-ecl and even 
textured, and in the main consists of quartz, but with traces 
of the same feldspar-like mineral found in the Santa Crux 
deposits. The grains are both sharp and round, and are ap- 
parently cemented by the bitumen alone. The per cent of bitu- 
men is nearly 15, and the rock is one of the best in appearance 
to be found in California. It is black on first fracture, weather- 
ing gray to brown. It is tough and tenacious and its use 
as a paving material is said to be satisfactory. The area occu- 
pied by the deposit and the local variations in its per cent of 
bitumen are undetermined. The sandstone itself is continu- 

*Asphalt and Bituminous Rock Deposits of the United States, try George 
H. Eldridge, pp. 379-407. 
tDitto pp. 407-412. 



I4 SOLID BITUMENS. 

ous over a region of many miles, of which this is a local en- 
richment. The composition, coarseness, interstitial space, and 
cross bedding have all influenced the degree of impregnation 
with bitumen which the rock has undergone. From the rela- 
tions of the enriched to the more barren portions, and of the 
latter to parts free from bitumen, the appearance is as though 
infiltration, after the accession of the bituu en, proceeded lat- 
erally along stratification planes, the mass of the flow seeking 
the channels that were freest. Similar phenomena are ob- 
served in Oklahoma. 

The bituminous deposits of the Santa Maria district em- 
brace two varieties : one a high grade black material, found 
in veins ; the other an impregnated shale. The two varieties 
may be found in the same locality, but the veins are especially 
developed in La Graciosa Hills. In the sandstone they arc 
particularly clearly developed and have the appearance of 
originating in cracks irregularly disposed through a mass of 
fairly coherent sand or sandstone. 

In the western portion of Santa Barbara County, in an 
area of about 15 by 20 miles, lying between the San Rafael 
and Santa Inez Ranges, is the Los Alamos district, the prin- 
cipal deposits of which occur on the Sisquoc and La Laguna 
ranches. On one of the richer portions of the Sisquoc sand- 
stones, the Alcatraz Co. has opened its quarry. The opening 
is in the southern face of a ridge, extending along its length 
several hundred feet. The rock exposed and quarried has a 
thickness of something over 100 ft., most of which is of good 
grade. The bitumen is said to be removed from the sand- 
stone at the quarry by means of naphtha, in which it is car- 
ried by a pipe line to a landing owned by the company, on the 
ocean front near Gaviota. It is there, according to account, 
separated by distillation, the recovered naphtha being pumped 
back to the quarry for further use as solvent and conveyor. 
The distance between the quarry and refinery is about 35 
miles. Other deposits of bituminous sandstone occur in the 
neighborhood.* 

At More's Landing, six miles west of Santa Barbara, on 
the coast are found extensive deposits of asphaltum contain- 

*Ditto, pp. 413-439. 



GEOGRAPHICAL DISTRIBUTION. 15 

ing varying amounts of sand. The bitumen occurs in veins 
which are exposed as the sand, forming the ocean bluff, is 
washed away. Originally large masses, that had a tabular 
form resting upon a sort of talus that extended into the sands 
below, were scattered over the bed of the ocean in front of 
this bluff, some of them above and others beyond low water 
mark. 

Three or four miles west of More's Landing, and ten 
miles west of Santa Barbara, the noted La Patera mine was 
worked for several years on a vein of asphaltum that was 
more or less irregular and intermittent, the maximum width 
being 12 ft. The trend of the main vein is N. 30 E. with a 
nearly vertical dip. Lateral cracks extend in all directions. 
The several shafts of the mine descend to a maximum depth 
of 500 ft. Below the loo-ft. level the tendency of the bitumen 
to swell in floors of the tunnels, required its constant removal. 
It is stated that a body of bitumen equal to the length and 
breadth of the tunnel and 20 ft. high has been removed in one 
year. This swelling of the bitumen is accompanied with an 
escape of gas, which has produced a distinctively porous con- 
dition of the bitumen of temporary duration. 

Fifteen miles east of Santa Barbara, at Carpinteria, on 
an ocean bluff, occurs another extensive deposit of loose sand 
saturated with a stiff maltha. The average thickness is about 
12 ft. It rests upon the upturned edges of the shales which 
are rilled with the holes made by bivalves so common in the 
bluffs along that coast. 

Five or six miles east of the above named deposit near 
Punta Gorda veins of bitumen have been worked to a depth 
of 100 ft. Several veins of bitumen of varying purity have 
been exploited in the hills bordering the San Buena Ventura 
River to the north of the town of Ventura. None of them 
have proved commercially valuable.* 

The Asphalto district lies in a semi-arid region on the 
western side of the San Joaquin valley about 50 miles west 
of Bakersfield. A careful examination of this locality was 
made by the author in July, 1894, during a visit of several 
days. 

*Ditto, pp. 440-447. 



!6 SOLID BITUMENS. 

The deposits of asphaltum were of two entirely distinct 
varieties. The first consisted of the residuum of an overflow 
of maltha which formed a sort of glacier which partially filled 
a canon. Although the mass of this material was of enormous 
dimensions, covering an area of more than a square mile and 
many feet in depth at the center, the outflow was geologically 
recent, as human remains, and mortars and other utensils 
had been uncovered from the gravel at the bottom of the mass 
of asphaltum. The springs from which the maltha had flowed 
that furnished the material for the deposit, were situated high 
up in the hills, and the maltha had spread out in the dry sea- 
son with overflows of dirt and rubbish when it rained until a 
vast mass of more or less impure asphaltum had accumulated 
in the canon below. During the i8th and early part of the 
1 9th centuries, when the entire country was used for grazing 
vast herds of cattle, the rancheros frequeptly set the surface 
of the maltha on fire to destroy the stickiness of the surface, 
as calves and sheep frequently lay down on the warm asphal- 
tum and becoming glued to the surface, starved to death. These 
fires must have produced a very intense heat, as beds of coke 
or cinders twelve inches in thickness are found intercalated 
with the asphaltum. Notwithstanding so much has been 
damaged or destroyed there are thousands of tons left in good 
condition in the glacier-like mass of the outflow. 

The second form in which the asphaltum occurs is in 
veins that outcrop in lines miles in length upon the sides of 
the almost barren hills. At the time of my visit several 
shafts had been sunk to a depth of about 90 ft. The veins 
were encountered in the galleries from 2 to 6 ft. in thickness, 
readily cleaving from the soft argillaceous sandstone which 
enclosed them. Since that time some of the shafts have been 
sunk much deeper, one of them to a depth of 300 ft. At this 
depth the teeth of a fossil horse were found enclosed in the 
asphaltum. At the time of my visit, in mid-summer, the 
temperature in the mine, at a depth of 90 ft., was sufficiently 
high to soften the bitumen in large masses. No water was 
encountered at that depth, and I have understood that none 
had been reached at the greater depth. The aggregate 
amount of bitumen in these hills seemed enormous ; but very 
conflicting statements, some of which have represented the 



GEOGRAPHICAL DISTRIBUTION. 17 

deposits as worked out, have been given as a reason why the 
mines are no longer worked. The true reason is, probably, 
wholly commercial. 

The out-crop of the veins and for some depth below the 
surface is decomposed into a brown friable mass, that on dry- 
ing breaks into approximately rhomboidal masses resembling 
siderite. At a varying depth this brown material passes into 
black cohesive asphaltum. At the time of my visit the asphal- 
tum averaged, from samples taken from the shafts by myself, 
nearly 90 per cent pure bitumen. All of the specimens con- 
tained alumina and iron in organic combination with the hy- 
drocarbons, and a small percentage of hygroscopic moisture. 

In British North America there are enormous deposits of 
bituminous sand in the valley of the Athabasca River. In 
New Brunswick the well known deposit of Albertite in the val- 
ley of the Peticodiac River in Albert County, was mined for 
many years. The material is a clean, pure asphaltum, jet 
black in color, with a brittle, conchoidal fracture. It was 
used as a crude material for the manufacture of illuminating 
oils, for which purpose it was found to be very valuable, until 
the discovery of petroleum in Pennsylvania rendered its man- 
ufacture unprofitable. It has never been used in paving. 

In the English West India Islands of Barbadoes and Trin- 
idad very extensive deposits of solid bitumen are found. The 
"munjack" of Barbadoes is a very pure, brittle, black asphal- 
tum. On the Island of Trinidad the celebrated "Pitch Lake" 
furnishes the well known Trinidad pitch in vast quantities. 
As it occurs in the lake it fills a circular depression, known 
to be more than 100 ft. deep in the center, and covering an 
area of 114 acres. It has been suggested by Mr. Clifford 
Richardson that the bitumen fills the crater of an old mud 
volcano. There are many phenomena observed that render 
this suggestion plausible. The bitumen is in constant mo- 
tion, rising in the center and falling at the sides, suggesting 
a slow ebullition. Copious springs of mineral water accom- 
pany the bitumen, and, saturating the mass, renders it plastic 
while at the same time large volumes of gas escaping in huge 
bubbles render the mass porous. For this reason the mass 
within the lake is called "cheese" pitch. On the northeast side 
the rim of the lake has been broken down and the pitch has 



T 8 SO Lin BITUMENS. 

flowed out, and downwards to the sea in a vast flood plain of 
unknown depth and spreading like a fan it covers several 
thousand acres. For commercial reasons this overflow pitch 
has been called land pitch, although there is no essential dif- 
ference in the clean pitch wherever it is found. The pitch is 
a unique substance. Nothing in the world resembling it is 
known to the author. It consists of bitumen, intimately 
mixed with organic salts of aluminia and iron with iron py- 
rites and silica in a very fine state of division, the mass con- 
taining a variable amount of water. When a mass is laid in 
the sun the surface dries out and melts, forming a film that 
prevents further evaporation, the color changing from brown 
to blue-black. The surface of the lake and overflow will sup- 
port a loaded team if kept in motion, but \vill yield to the 
weight of a man if he stands still for a short time. It is esti- 
mated that the lake and overflow contain several million tons 
of pitch. Bitumen resembling munjack is also found on the 
island of Trinidad. 

On the main land of Venezuela, west of the bay of Paria 
in the state of Burmudez, extensive deposits of asphaltum 
occur, also in the western part of Venezuela on Lake Maricabo 
and the Magdalena River other extensive deposits are found. 

In the island of Cuba, veins of asphaltum of large extent 
have been known for many years. Extensive deposits of as- 
phaltum of great purity are also known to occur under water 
in the harbors of Havana and Cardenas. There are also ex^ 
tensive deposits of asphaltum at several localities in Mexico, 
near the coast of the Gulf of Mexico in the states of Tamau- 
lipa and Vera Cruz. Dr. J. P. Kimball described in 1876 a 
vein of asphaltum as a deposit of Grahamite known as the 
Cristo Coal Mine.* 

Deposits of very pure asphaltum occur in Egypt. There 
are no others reported from the African continent. 

There are a number of localities in Europe-Asia, some 
of which are commercially of great importance. From an 
immemorial period very pure asphaltum has been cast up on 
the shores of the Dead Sea. Formerly it entered the com- 
merce of that region, but for some years the amount obtained 

*Private Report, New York, May, 1876. 



GEOGRAPHICAL DISTRIBUTION. 19 

from this source has been decreasing until it is no longer of 
importance. Asia Minor, Persia and the regions that border 
the valleys of the Euphrates and Tigris Rivers abound in de- 
posits of solid bitumen, locally valuable. Extensive deposits 
are reported to exist in the mountains of Albania. Extensive 
quarries of bituminous rock are found at Ragusa in the island 
of Sicily, also at Limmer in Hanover. The most important 
deposits of bituminous rock in Europe are those of the upper 
valley of the Rhone at Pyrimont and Seyssel. The most valu- 
able rock is a chalk saturated with bitumen, that is interstrati- 
fied with sand and conglomerate that are also saturated. 
Eirinis d' Erynys, a Greek physician, published in Paris, in 
1 721, a pamphlet in which he described these deposits of sand 
and limestone saturated with bitumen that he had discovered 
some years before.* He further describes a bituminous dis- 
tillate that he had prepared from this rock, which he used with 
very satisfactory results in the treatment of certain forms of 
disease. He compares these deposits to similar beds in the 
valley of Siddim near Babylon, and remarks that the mine of 
asphaltum is for Europe a treasure that has been unknown to 
us from the beginning of the world. These deposits were 
forgotten for nearly a century and were then rediscovered. 
They have since become of great commercial importance. 
Other European localities furnishing asphaltum and bitumin- 
ous rock are not of commercial value. 

The geological age of the different deposits of solid bitu- 
mens is an interesting study. Beginning with the extreme 
eastern deposit of Albertite it is found in a region that abounds 
in beds of coal of vast extent in the true coal measures. Pro- 
ceeding westward across the continent of North America, the 
vein of Grahamite found in West Virginia was also in the coal 
measures. Continuing westward to the Oklahoma the exten- 
sive deposits found there are also in the coal meas- 
ures. The deposits of Gilsonite and allied bitumens of Colo- 
rado and Utah are in the Cretaceous as are also those of central 
Texas. The bitumens of the Coast Range of California are 
found in formations from the Cretaceous up to the Quaternary. 

*Dissertation sur 1'asphalte ou cement naturel decouvert depuis quel- 
ques annees au Val-Travers, dans le comte de Neufchatel par le sieur 
Eirini d' Erynys, professeur grec et docteur en medicine, Paris, 1721. As- 
phaltes et Naphtes, par Isidore Huguenet, Paris, 1852. 



2O 



SOLID BITUMENS. 



The bitumens of Cuba are found in formations not older 
than the Cretaceous while those of the other West India 
Islands and of Venezuela occur in formations that are later 
than the Cretaceous. 

The formations in which the Dead Sea lies are Cretaceous, 
witli eruptive masses, indicating active volcanic action at 
a recent geological epoch. 

The bitumen of Albania and the east coast of the Adriatic 
Sea is found in formations none of which are older than the 
Cretaceous. The important bituminous limestones of the val- 
ley of the Rhone are Cretaceous, while those of Hanover are 
Triassic. 

From what has preceded, the conclusion may be reached 
that large accumulations of solid bitumens and bituminous 
rocks are found in nearly every member of the geologic series 
from the Silurian to the Quaternary, but that there have been 
three especially prolific periods of activity when solid bitu- 
mens accumulated and were forced into crevices which had 
rent the surface of the earth with explosive violence. These 
were first, at a period subsequent to the deposition of the Coal 
Measures ; second, during the deposition of the Cretaceous or 
later; and third, during the deposition of the Tertiary or later. 
The bitumens of these three epochs are characterized by 
marked peculiarities that will be discussed under the general 
considerations relating to the chemistry of bitumens. 



CHAPTER II. 
THE ORIGIN OF BITUMENS. 

The origin of bitumens has been a fruitful subject* of 
speculation among scientific men for more than half a cen- 
tury. Generally speaking, the theories advanced fall into 
three classes, embracing those which regard bitumen as a 
distillate produced by natural causes, those which regard bitu- 
men as the product of a peculiar decomposition of organic 
matter within the formations in which the organic matter is 
enclosed, making the bitumen in a sense indigenous to the 
rocks in which it is found, and those which regard bitumen 
as a product of chemical reaction, the latter class being sub- 
divided into those which regard bitumen as a product of chem- 
ical change in natural substances of which carbon and hydro- 
gen are constituents, and those which advocate a purely chem- 
ical reaction between purely mineral or inorganic materials. 

Whatever theories are held with reference to the origin 
of bitumens, no distinction can be made in the different classes 
of bitumens, but all of the varieties, from natural combustible 
gas through naphtha, petroleum and maltha to solid asphal- 
tum, must be included in one common source. 

"The argument for a purely chemical origin of bitumen 
was first brought to the serious attention of scientific men, 
through the publication of a noted paper by the distinguished 
French chemist Berthelot in 1866.* Among others the most 
conspicuous advocate of this theory has been Mendeljeff, who 
read a paper on the origin of petroleum before the Chemical 
Society of St. Petersburg, of which the following is a resume. 

The appearance of springs of petroleum at the surface of 
the earth shows the tendency of those mineral oils to traverse 
by infiltration the different strata of the earth in reaching 
the surface, a natural consequence of their lower density as 
compared with water. The place where petroleum originates 

*S. F. Peckham, Report on the Production, Technology and Uses of 
Petroleum. Reports of 10th Census U. S., 1885, x, p. 63. 

21 



22 SOLI/) H/Tl'MJL\S. 

ought then to be situated beneath the strata where the springs 
themselves are found. The beds furnishing the mineral oil 
belong in general to several different formations of the earth's 
strata. Thus, in the Caucasus, the petroliferous zone is 
found in the Tertiary ; in Pennsylvania, in the Devonian, and 
even Silurian. The place of the formation of the petroleum 
ought then to be sought in other strata. The sandstones im- 
pregnated with petroleum have never exhibited the carbon- 
ized remains of organisms. In general, petroleum and car- 
bon are never found simultaneously ; but it is difficult to sup- 
pose that petroleum has resulted from the decomposition of 
animal and vegetable organisms, because it would then be 
impossible to represent the origin of petroleum without a 
corresponding formation of carbon. On the other hand, it is 
impossible to imagine the existence of great quantities of 
organisms in the epoch preceding the Silurian and Devonian. 
These reflections have led the author to the supposition that 
petroleum is in no place of organic origin. In speaking of 
the hypothesis of La Place upon 'the origin of the earth, in 
applying Dalton's law to the gaseous state in which all the 
elements constituting the terrestrial globe ought to be found, 
and taking into consideration their relative densities, Mendel- 
jeff recognizes the necessity of admitting a condensation of 
metals at the center of the earth. Among these it is natural 
to presume iron would predominate, because it is found in 
great abundance in the sun, in meteorites and basalts. Ad- 
mitting further the existence of metallic carbides, it is easy to 
find an explanation not only for the origin of petroleum, but 
also for the manner of its appearance in the places where the 
terrestrial strata, at the time of their elevation into mountain 
chains, ought to be filled with crevices to their center. These 
crevices have admitted water to the metallic carbides. The 
action of water upon the metallic carbides at an elevated tem- 
perature and under a high pressure have generated metallic 
oxides and saturated hydrocarbons, which, being transported 
by aqueous vapor, have reached those strata where they would 
easily condense and impregnate beds of sandstone, which have 
the property of imbibing great quantities of mineral oil." 

This and other chemical theories are supported by great 
names and are based on the most complete and elaborate re- 



THE ORIGIN OF BITUMENS. 23 

searches ; but they require the assumption of operations no- 
where witnessed in nature or known to technology.* 

The most conspicuous advocate of the theory that bi- 
tumens are a product of chemical reaction, by which marsh 
gas is converted into more condensed hydrocarbons, appearing 
as fluid, viscous, and solid bitumens is Coquand, who has writ- 
ten so fully upon the occurrence of bitumen in Roumania and 
Albania. He found mud volcanoes associated with the occur- 
rence of bitumen in Sicily, the Appenines, the peninsula of 
Taman, and the plains of Roumania, and concluded that mud 
volcanoes produce petroleum and other forms of bitumen by 
converting marsh gas into more condensed hydrocarbons. 

It may be said, in reference to this theory, that, in so far 
as it expresses the fact that maltha represents an intermediate 
stage in the transformation of some varieties of petroleum 
into asphaltum and recognizes the chemical relation existing 
between marsh gas and the different forms of bitumen, it is 
entitled to consideration ; but, in the chemical processes of 
nature complex organic compounds pass to simpler forms, of 
which operation marsh gas, like asphaltum, is a resultant, and 
never the crude material upon which such decomposing forces 
act.f 

Most conspicuous among the advocates of the theory that 
bitumen is indigenous to the rocks in which it occurs are Drs. 
T. Sterry Hunt and J. P. Lesley. These very eminent gentle- 
men based their views upon observations made in Canada, 
West Virginia and Kentucky. J 

Conspicuous among later writers who advocate this view 
will be found Jaccard, the Swiss geologist who wrote so exten- 
sively upon the bituminous deposits of the upper valley of the 
Rhone, Dr. Edward Orton, late geologist of the State of Ohio, 
and Dr. Charles F. Mabery. The last named gentleman stated 
his views at length'in a paper read before the American Philo- 
sophical Society, April 3, 1900, from which the following is 
quoted : 

"Much as has been said on this attractive subject, a 

*Bul. Soc. Chem. de Paris, 1877. 501. S. F. Peckham. Rep. 10th Census 
U. S., Vol. X, p. 61. 

!Bul. Soc. Geol. de France, xxv, 35. 

JSee Report on Petroleum, by S. F. Peckham, Reports U. S. Census 1880, 
x, 62. 



24 SOLID BITUMENS. 

broader knowledge of facts is necessary before definite con- 
clusions can be reached. What is known forms the basis for 
only one explanation concerning the formation of petroleum, 
and that is, that it was formed from vegetable or animal matter 
by slow decay or breaking down from the complex forms of 
vegetable or animal life under the influence of natural forces, 
with no great elevation in temperature such as is necessary for 
distillation. 

"MendeljefFs theory of the formation from carbides at 
high temperatures, recently asserted with greater force on the 
basis of Moissan's work with the electric furnace, demands 
too many hypothetical assumptions, and has too little support 
on the basis of fact. To reason from the artificial formation 
of alloys and carbides in an electric furnace to the natural 
formation of petroleum containing nitrogen, sulphur and 
oxygen, in the form of hydrotheophenes, hydrochinolines, and 
phenols, demands a too broad reach of the imagination to 
make the connections. 

"Bearing in mind the fact that petroleum may now be 
regarded as one and the same substance whatever its source, 
and that the deposits in different fields are composed of the 
same series, differing only in the proportions of these con- 
stituents, it must be admitted that it had one origin and one 
only. With reference to the series of hydrocarbons, it is im- 
material whether its source was animal or vegetable, for under 
the influence of natural agencies it could have been formed as 
well from one as from the other. 

"This question has been attacked on chemical grounds 
from the wrong direction. Because hydrocarbons of the marsh 
gas series, ethylene series or acetylene series at temperatures 
of decomposition form minute quantities of the aromatic series, 
or that hexahydroaromatic bodies are formed from the aro- 
matic hydrocarbons by heating with hydriodic acid, to assume 
that these changes were produced by natural agencies and 
resulted in the formation of the hydrocarbons which now con- 
stitute petroleum, together with the other constituents of 
petroleum, ascribes to these natural agencies a direction of 
action and power that we do not know they possess. 

"In considering present knowledge with reference to the 



THE ORIGIN OF BITUMENS. 25 

natural formation of petroleum, it seems to me that the follow- 
ing questions must be answered : 

"(i) What is the chronology of petroleum; in what order 
were the deposits formed in different fields? 

"(2) Were the least volatile constituents formed from the 
most volatile or the reverse? 

"(3) What is a reasonable explanation of the formation 
of the other constituents of petroleum? 

"The first question must be answered by the geologist. 

"It is natural to assume that the limestones formed by 
the accumulations of the shell remains of animal life were 
deposited first from the ancient sea. The sand stones, as 
products of erosion from the older rocks, were deposited last. 
The question as to whether the different deposits of petroleum 
were formed in situ, or formed in other strata and by some 
natural agency transferred to their present location, has not, 
I believe, been satisfactorily answered by the geologists. In 
the case of the limestone petroleum, it would seem that it 
must have been formed where it is now found, as Hunt and 
Orton have ably maintained. 

"The theory of distillation from some other strata is not 
tenable in the light of present knowledge of the constituents 
of petroleum. Neither could any known constituents of plants 
that could form petroleum be distilled, nor could the heavier 
portions of petroleum be distilled ; the result would be only 
very volatile distillates and deposits of coal or graphite. In 
this condition deposits of petroleum should always be accom- 
panied by coal, or with coal in the near vicinity. 

"In the case of Pennsylvania and the allied southern Ohio 
and West Virginia petroleum, it would be a great discovery 
to connect these deposits with the coal formation, for then 
the source would unquestionably be vegetable growth, and 
would support the opinion that this was the source of petrol- 
eum of this class. It is reasonable to assume, as is now be- 
lieved, that Pennsylvania oil was not formed in the sandstones, 
but found its way there by natural agencies from lower strata, 
probably the Devonian shales. The infiltration of the crude 
oil through sandstones, would have a purifying effect. It is 
quite probable that the very light yellow crude oils from the 



26 

Berea Grit and other sandstones were filtered a second time 
or more into their present positions. 

"With reference to the source of the limestone oils, the 
evidence is all in favor of animal origin, and the same is true 
of California oil, although its formation is far more recent 
than that of the others. Texas petroleum has not been suf- 
ficiently studied in relation to its occurrence and composition, 
but it is evidently of more recent origin, like California oil. 

"With reference to the second question, is it more rea- 
sonable to assume, for instance, that the solid paraffine hydro- 
carbons were formed from the lower members of this series, or 
that the lower members were formed from paraffine? On this 
point some experimental evidence may be brought to bear. 
Reichenbach obtained paraffine from both vegetable and 
animal organic matters. Engler obtained paraffine by the dis- 
tillation of fish oil, as Warren and Storer had done many 
years previously. 

"It is well known that paraffine breaks down very readily 
into hydrocarbons with lower molecular weights, but it is not 
possible to polymerize the lower hydrocarbons into the solid 
paraffine hydrocarbons. The tendency in cracking of any 
constituents of petroleum is toward the formation of the lower 
series and finally carbon in the form of coke. So far as experi- 
mental evidence and observation have shown the nature and 
relations of the hydrocarbons which compose the different 
series in petroleum, the conclusion is convincing that the 
lower members of the series were formed from the higher. A 
single break in the ring of a methylene is sufficient to form by 
the addition of hydrogen a paraffine hydrocarbon. 

"In answer to the third question, as to the formation of 
the sulphur, nitrogen and oxygen compounds in petroleum, 
these bodies have not been built up synthetically, but are 
the products of decomposition of more highly organized con- 
stituents of organic bodies. It would seem that the small pro- 
portions of these bodies in Pennsylvania oil, as compared with 
the larger proportions in limestone oils and California oil, 
should be strong evidence in favor of a different origin, that 
Pennsylvania oil came from organic vegetable remains, which 
should permit of the small amounts of sulphur and nitrogen 
compounds found in this class of oils. 



THE ORIGIN 01' BITUMENS. 



27 



"But I think it can be asserted as a fact that the very 
large proportion of nitrogen in California petroleum, amount- 
ing to one-fifth or more of the total weight of the oil, can only 
be accounted for by accepting animal remains as the source 
of their formation. As a summation of what is at present 
known of the origin of petroleum, the following answers may 
be given to the questions propounded above: 

"(i) Petroleum containing large proportions of the vol- 
atile hydrocarbons, especially of the series Cn H 2 n-}-2, such as 
Pennsylvania petroleum, was formed from vegetable organic 
matter. The limestone petroleum and California petroleum 
was formed from organic matter of animal origin. 

"(2) Cellulose, starch and other similar bodies in plants, 
and the fats and nitrogen compounds in animal bodies, by 
gradual decomposition with exclusion of air, gave first the 
heavier bodies found in petroleum, and by natural agencies 
during long periods of time, with no considerable rise in tem- 
perature, further decomposition included as products the 
hydrocarbons with smaller molecular weights. 

"(3) The nitrogen and sulphur constituents of petroleum 
could only have been formed directly from or through the 
agency of animal organic matter. "* 

For the consideration of this subject we are greatly in- 
debted to the profound and skillful chemical researches of 
Dr. Mabery. His conclusions, however, are based too exclu- 
sively on the results of chemical research upon petroleum 
alone. All forms of bitumen from marsh gas to solid 
asphaltum have a common origin and that origin should be 
discussed as a phenomenon of the cosmos upon which geol- 
ogy, technology, mineralogy and chemistry cast strong side 
lights, and together yield the testimony upon which conclu- 
sions may be based. The following is a general review of the 
subject: 

In view of the general acceptance of the nebular hypothe- 
sis, it is unnecessary to establish the fundamental proposition 
that bitumens, as minerals, are properly considered in their 
relation to all the other mineral species that have been identi- 
fied and described as together constituting the earth's crust. 

*Proc. American Philosophical Society, xlii, 36. 



28 SOLID BITUMEXS. 

The clear distinction of these relations has followed upon 
many years of research along several lines. It began more 
than a century ago with the famous discussion waged between 
the Plutonists and Neptunists, as to whether fire or water had 
been most active in producing the phenomena of rock build- 
ing. Mineral silicates were then supposed to have crystal- 
lized from igneous fusion, and the deposition of sediments 
to have resulted only in amorphous, uncrystallized rock. The 
idea that heat and water together may have produced all of 
the phenomena that have been attributed to the action of 
either alone has been of slow growth ; but may now be said 
to be pretty generally accepted, although there are those who 
refer to the action of heat and of pressure alone phenomena 
that are without doubt properly the resultant of the action 
of heat and steam under pressure. 

The discussions that have proceeded along the three lines 
of geology, chemistry and mineralogy, have been mainly di- 
rected to an elucidation of the problems relating to the forma- 
tion of the crystalline rocks. To determine, therefore, the 
nature of metamorphic action and the conditions under which 
it might take place, was the problem to the solution of which 
Bischof, Hunt. Delesse, Daubree and several others of the 
most gifted chemical geologists of the last century devoted 
themselves.* These gentlemen first considered the reactions 
that according to known chemical laws must follow the cool- 
ing of a heterogeneous mixture of the elements composing 
the earth, in a state of gaseous fluidity, and at a temperature 
that rendered chemical combination impossible ; in other 
words, a state of complete dissociation. It follows that the 
most infusible elements would first condense and form a solid 
nucleus around which would float an ocean, in a state of 
igneous fusion, of more fusible elements and compounds, 
while over all would hover an atmosphere containing all the 
nitrogen and oxygen, the free hydrogen, sulphur and allied 
elements, with the chlorine and other halogens. As the cool- 
ing proceeded the silicon would combine with oxygen and 



*G. Bischof, Chem. and Phys. Geology, Cav. Soc. ed. T. S. Hunt, Chem. 
and Geolog. Essays. Delesse, "Essay on Pseudomorphs." Ann. des Mines, 
xii, 509; xiii. 393, 415; xvi, 317-392. Mem. Acad. de Scien. de France, xvii. 
Daubre, Comptes Rendus de 1' Acad., November 16, 1857. Etudes et Ex- 
periences synthStique sur le M6tamorphisme, Paris, 1859. 



THE ORIGIN OF BITUMENS. 29 

bases, forming both acid and basic silicates, which would con- 
stitute a solid crust. The hydrogen and haloids combining 
would form the haloid acids and the sulphur and allied ele- 
ments would form oxygen acids, all the hydrogen being oxi- 
dized into water, which with the acids would be alternately 
condensed and evaporated, falling as an acid rain upon the 
surface of silicated rocks, which in turn would emerge from 
the ocean of water heavy with dissolved chlorides and sul- 
phates, while an atmosphere dense with carbonic acid would 
help to maintain a temperature that would retard the cooling 
through vast cycles of geologic time, in the course of which, 
under conditions entirely different from any now known, 
vegetable and animal life would appear upon the earth, or, 
more properly, in the waters that covered the earth. 

It is very evident that the chemical conditions obtaining 
in this remote geologic epoch, while not incompatible with 
the development of life, were, however, very different from 
those which have prevailed at any time since the advent of 
any of the higher forms of animals. We have a right to be- 
lieve that at the dawn of life, of all the elements that enter 
into the composition of vegetable and animal tissue carbon, 
hydrogen, oxygen, nitrogen, phosphorus and sulphur ni- 
trogen alone was wholly free. Carbon and hydrogen existed 
in combination with oxygen as carbonic acid and water. 
Phosphorus and sulphur were oxidized, and in combination 
with basic elements as salts. The excessive proportion of car- 
bonic acid and aqueous vapor in the atmosphere gave to it 
the property of transcalesence, by which, while readily pene- 
trated by heat from the sun, it refused to transmit this heat 
when reflected from objects at the earth's surface. This gave 
to the atmosphere properties similar to those of a greenhouse, 
by which so high a temperature was maintained during the 
coal period that semitropical plants flourished at the poles. 
At an earlier period, before terrestrial vegetation had removed 
the carbonic acid from the air, and before the surface of the 
cooling earth had lost its heat by radiation, the palaeozoic 
(dawn of life) ocean and the land gave support to both vege- 
table and animal life, at a temperature that at the present 
time would destroy most organic forms.* 

*W. H. Brewer, Am. Jour. Sci. (2), xli, 389. 



30 SOLI/) BITUMENS. 

The strata which form that portion of the earth's crust 
which has been referred to the palaeozoic era, are of enormous 
thickness and are found in different parts of the world, to pre- 
sent aspects strikingly similar. Messrs. Hall, Billings and 
Dawson, in North America, Salter and Hicks in England, 
Angelin in Sweden, and Barrande in Bohemia, have shown that 
the forms of animal life in that early period were very closely 
related, if not identical, in these widely separated areas; yet, 
below these formations, which hold the remains of marine 
animals, in Bohemia and Sweden if not elsewhere, there is a 
"region of fucoids," of great thickness, carrying back the dawn 
of vegetable life to a still more remote epoch.* Throughout 
the last, fifty years, successive discoveries of fossils in strata 
hitherto supposed to be destitute of organic remains, have 
carried the apparent dawn of life back through successive geo- 
logical formations, until the azoic (devoid of life) rocks have 
ceased to be appropriately named, and Mr. Hicks, speaking of 
the Cambrian fauna of Wales, says, "Though animal life was 
restricted to these few types, yet at this early period the rep- 
resentatives of the different orders do not show a very diminu- 
tive form, or a markedly imperfect state ; nor is there an in- 
creased number of blind species. The earliest known brach- 
iopods are apparently as perfect as those which succeed them ; 
and the trilobites are of the largest and best developed types. 
The fact also that trilobites had attained a maximum size at 
this period, and that forms were present representative of 
almost every stage of development, .... blind genera 
along with those having the largest eyes, leads to the conclu- 
sion that for these several stages to have taken place numer- 
ous previous faunas must have had an existence, and, more- 
over, that even at this time in the history of our globe an 
enormous period had elapsed since life first dawned upon it." I 
The formations that contain these earliest palseozoic 
forms of life are now found for the most part in a crystalline 
condition ; yet, Dr. Hunt affirms, "the oldest known rocks are 



*James Hall, Paleontology of New York, Vol. iii, Introduction. Billings, 
Am. Jour. Sci. (2), xxxii, 232. Dawson, Canadian Naturalist, v. d. Reports 
Geological Survey of Canada, v. d. Salter and Hicks, Proc. Geol. Assoc., 
Quar. Jour. Geolog. Soc., v. d. Angelin Palaeontologica Scandinavica. Bar- 
rande, Bui. Soc. Geol. de France (2), xvi, 529-545. 

fHicks, Quar. Jour. Geol. Soc., May, 1872. 



THE ORIGIN Ol' BITUMENS. 3! 

stratified deposits of limestone, clay and sands, generally, in 
a highly altered condition ; .... it is, however, quite 
certain that the advent of life in these oldest fossiliferous 
strata was subsequent to the period of chemical reactions on 
a cosmic scale.''* The manner in which these geological 
formations and parts of formations may have been rendered 
crystalline has been very exhaustively discussed by Dr. Hunt 
in his chemical and geological essays. He has shown how 
fully his conclusions, based almost wholly on theoretical con- 
siderations, have been confirmed by the experiments of Dau- 
bree, who was led to investigate this subject, from observing 
that the action of the alkaline, thermal waters of the spring 
at Plombieres, at a temperature of 6o-7o C., had in the 
course of centuries given rise to the formation of zeolites and 
other silicated minerals among the bricks and cement of the 
old Roman baths. t He further shows that at a temperature 
of 100 C. silicates are produced from a reaction between 
alkaline silicates and carbonates of lime, magnesia and iron. 
He says further, "Now the supposed mode of formation of 
the primitive molten crust of the earth would naturally ex- 
clude all combined or intermingled water, while all the sedi- 
mentary rocks are necessarily pervaded by this liquid, and are 
consequently in a condition to be rendered semifluid by the 

application of heat If now, we admit that all 

igneous rocks, ancient plutonic masses as well as molten 
lavas, have their origin in the liquefaction of sedimentary 
strata we at once explain the diversities of their composition. 
. . . . The presence of fossil plants in the melting strata 
would generate carburetted hydrogen gases, whose reducing 
action would convert the sulphurous acid into sulphuretted 
hydrogen ; or the reducing agency of the carbonaceous matter 
might give rise to sulphuret of calcium, which would be, in 
its turn, decomposed by the carbonic acid or 'otherwise. 
The carburetted hydrogen and bitumen evolved from mud 
volcanoes, like those of the Crimea and Baku, and the car- 
bonized remains in the moya of Quito, and in the volcanic 
matters of the island of Ascension, not less than the infusorial 

*Chemical and Geological Essays, ed. 1875, p. 2. 

tEtudes -et Experiences synthEtique sur le metamorphieme, par M. A. 
Daubree, Paris, 1859, p. 98; Ann. des Mines (5), xiii, 227. 



32 SOLID BITUMENS. 

remains found by Ehrenberg in the ejected matters of most 
volcanoes, all go to show that fossiliferous sediments are very 
generally implicated in volcanic phenomena."* Again, he 
states, that "in a letter to Sir Charles Lyell, dated February 
20, 1836, Sir John F. W. Herschel maintains that with the 
accumulation of sediments the isothermal lines of the earth's 
crust must rise, so that strata buried deep enough will be 
crystallized and metamorphosed, and eventually be raised 
with their included water to the melting point." Again Dr. 
Hunt says, "We conceive that the earth's solid crust of an- 
hydrous and primitive rock is everywhere deeply concealed 
beneath its own ruins, which form a great mass of sedimen- 
tary strata, permeated by water. As heat invades these sedi- 
ments, it produces in them that change which constitutes 
normal metamorphism. These rocks at a sufficient depth are 
necessarily in a state of igneo-aqueous fusion, and in the event 
of fracture of the overlying strata may rise among them tak- 
ing the form of eruptive rocks. "f He calls the effects pro- 
duced by such invasion of eruptive masses, local metamorph- 
ism. From these extracts from several of Dr. Hunt's essays, 
it can be easily understood that a struggle has been in prog- 
ress from the time of the oldest known rocks to the present, 
between the shrinking and wrinkling crust of a cooling earth 
and the thickening deposits of sediment accumulating from 
its erosion. 

One Sunday in the early summer of 1866, the author, 
together with Dr. George L. Goodale, late of Harvard Uni- 
versity, were stranded at a small hostelry, at the San Fer- 
nando Pass, near the old Mission of San Fernando, in south- 
ern California. The day was very fine and we chose a morn- 
ing climb to anything the hostelry had to offer ; so, mounting 
our horses, we rode to the eastward over the flood plain of 
pulverized rock that at some former period had poured out 
of the great canon back of where the town of Burbank now 
stands. We climbed one of the spurs of the San Rafael range 
to the west of the canon. We first passed over rounded 
hillocks of sandy soil which as we ascended became gradu- 

*Essays, p. 8. 
tKssays, p. 9. 



THE ORIGIN OF BITUMENS. 33 

ally merged into soft fossiliferous sandstone. After a time 
the effects of heat became manifest. The clam shells and 
fossil clams, of which there were cart-loads, appeared crys- 
talline, and the iron in the sand was no longer green but red. 
The sandstones became more dense and the clays were sili- 
cated. At length the strata passed into a micaceous gneiss 
and finally we found the central core of the mountain to be 
a light-colored fine-grained granite. About half way up, Dr. 
Goodale found a vertebra of a whale half buried in the sand- 
stone and still very perfect in form, while the author found a 
fossil pine cone that had evidently received some rough usage 
on the ancient beach. This cone contained some seeds that 
showed it to be closely allied to the nut pine of New Mexico. 
The mountain consisted wholly of Tertiary sediments that 
had been metamorphosed precisely as Sir J. F. W. Herschel 
haS suggested in his letter to Sir Charles Lyell. 

It is not alone through a study of the crystalline rocks 
that the chemistry of the primeval world is interpreted. By a 
comparison of the kind and amount of salts dissolved in the 
waters of the primeval ocean that are enclosed in palaeozoic 
strata with the kind and amount of salts dissolved in the 
waters of the present ocean, Dr. Hunt has shown that from 
the earliest geologic time until the present, alkaline carbon- 
ates derived from the subaerial decomposition of feldspar have 
been carried into the ocean by streams, and the calcium and 
magnesium in the ocean have been successively precipitated as 
carbonates, producing limestones and dolomites, while com- 
mon salt and calcium sulphate have accumulated in the pres- 
ent ocean, the former in large excess. There is abundant evi- 
dence that this palaeozoic ocean was hotter than the existing 
one, as well as more saline, while it is equally evident that 
during long intervals its sediments carried down vast 
quantities of the remains of vegetable and animal life. He 
further repeatedly has shown in what manner these sediments 
were influenced by the organic matters that were enclosed in 
them. In his essay on "The Chemistry of Natural Waters," 
he has shown that argillaceous sediments deprive waters of 
the 'organic matter in solution by forming a compound con- 
taining an organic radical. He says, "There is reason to 
believe that alumina is under certain conditions dissolved by 



u SOLID BITUMENS, 

waters holding organic acids," and cites melite and pigotite 
as examples of the compounds formed. He further shows 
that organic matter in water reduces sulphates to sulphides, 
producing from soluble sulphates of lime and magnesia car- 
bonates of the bases, with hydrogen sulphide, free sulphur, 
or a metallic- sulphide ; the hydrogen sulphide being converted 
by slow oxidation or combustion, followed by absorption of 
oxygen directly into sulphuric acid, which is again, when in 
contact with organic matter, reduced to hydrogen sulphide. 

He says with reference to the water of paleozoic brine 
springs, "In the large amount of magnesium chloride which 
they contain, these waters resemble the bittern or mother- 
liquor which remains after the greater part of the sodium 
chloride has been removed from sea-\vater by evaporation. 
.... The complete absence of sulphates from many of the 
waters points to the separation of large quantities of eafthy 
sulphates in the Cambrian strata from which these saline 
springs issue ; and the presence in many of the dolomite beds 
of the calciferous sand rock of small masses of gypsum, abun- 
dantly disseminated, is an evidence of the elimination of sul- 
phates by evaporation The brines of the valley of the 

Allegheny River, obtained from borings in the coal forma- 
tion, are remarkable for containing large proportions of 
chlorides of calcium and magnesium, though the sum of these, 
according to the examples given by Lenny, is never equal 
to more than about one-fourth of the chloride of sodium. The 
presence of the sulphates of barium and strontium in these 
brines, and the consequent absence of soluble sulphates, is, 
according to Lenny, a constant characteristic in this region 
over an area of 2,000 square miles."* 

Among many other illustrations that might be given of 
these non-sulphated palaeozoic waters, I mention one which 
was obtained from a boring on Great Manitoulin island in 
Lake Huron, at a depth of 192 feet, "After passing through 
the black slates of the Utica formation, and for 60 ft. into 
the underlying Trenton limestone it contained no sul- 
phates nor barium nor strontium." Another palaeozoic water 
of a very different character was obtained from a well bored 

Bischof -Chem. and Phys. Geol., i, 337. Hunt, Chem. and Geol. Essays, 
p. 121, ed. 1875. Am. Jour. Sci., March, July and Sept., 1865. 



THE ORIGIN OF BITUMENS. 35 

for petroleum at Hothwell, ( hit., in 1865. "At a depth of 4/5 
ft. from the surface, and probably at or near the base of the 
Corniferous limestone, a copious spring was met with, of 
very sulphurous water and a little petroleum." The water 
contained sulphate of calcium and sulphides of sodium and 
hydrogen. Waters apparently similar are pumped from sev- 
eral of the oil wells in the vicinity. "The sulphurous impreg- 
nation is doubtless to be ascribed to the reducing action of 
hydrocarbonaceous matter upon the sulphates which the wat- 
ers contain."* 

A brief examination of the superposition of the palaeozoic 
and earlier formations of North America will show the Lau- 
rentian, embracing the oldest known rocks of the globe, out- 
cropping from the coasts of Labrador to Lake Superior and 
over a large area in northern New York. Associated with 
this system is the Norian, which is characterized by a great 
development of opalescent feldspars. Above these are the 
Green Mountain series, an inferior part of the Lower Silu- 
rian, which corresponds wholly or in part to the Huronian 
system of Canada and the region about Lake Superior. 
Above these are the White Mountain series, which are Upper 
Silurian and perhaps Devonian. These formations constitute 
for the most part the rocks of Canada, New England, eastern 
New York and the eastern slope of the Alleghenies southward 
through New Jersey, Pennsylvania and Virginia. Speaking 
of these rocks, Dr. Hunt says, "In the oldest known of them, 
the Laurentian system, great limestone formations are inter- 
stratified with gneisses, quartzites and even with conglomer- 
ates. All analogy, moreover, leads us to conclude that, even 
at this early period, life existed at the surface of the 
planet. Great accumulations of iron oxide, beds of metallic 
sulphides and of graphite, exist in these oldest strata, and we 
know of no other agency than that of organic matter capable 
of generating these products. f .... Bischof had already ar- 
rived at the conclusion, which in the present state of our 
knowledge seems inevitable, 'that all the carbon yet known 
to occur in a free state can only be regarded as a product of 

*Essays, 158-163, ed. 1875. 

tOn the north shore of Lake Superior, I have found spherical concre- 
tions of graphite occurring in a rock that is apparently eruptive. 



36 SOU I > BITUMENS. 

the decomposition of carbonic acid, and as derived from the 
vegetable kingdom.' He further adds, living plants, decom- 
posed carbonic acid, dead organic matters, decomposed sul- 
phates, so that, like carbon, sulphur appears to owe its exis- 
tence in the free state to the organic kingdom.' As a decom- 
position (deoxidation) of sulphates is necessary to the pro- 
duction of metallic sulphides, the presence of the latter, not 
less than of free sulphur and free carbon, depends on organic 
bodies; the part which they play in reducing and rendering 
soluble the peroxide of iron, and in the production of iron 
ores, is moreover, well known. "* 

Rocks of the Lower Cambrian in Great Britain as well as 
in North America are well known to exhibit carbonaceous re- 
mains. Of the former it is said, ''They occasionally hold 
flakes of anthracite, and small portions of mineral pitch ex- 
ude from them in some localities." The rocks of the Malvern 
hills contain fucoids. In the Quebec series on the south shore 
of the St. Lawrence, Hunt describes the occurrence of a car- 
bonaceous substance, "entirely distinct from coal, which oc- 
curs in fissures, sometimes in the interstices of crystalline 
quartz. It is an insoluble hydrocarbonaceous body, brilliant, 
very fragile, giving a black powder, and results apparently 
from the alteration of a once liquid bitumen. "f Similar ma- 
terial often lines cavities in the limestone in Herkimer Co., 
N. Y., and not only sometimes encloses crystals of quartz, 
but is often enclosed in quartz crystals. These limestones 
are not crystalline. 

Above these formations just mentioned, in the carbonifer- 
ous formation of both Europe and North America, anthracite 
occurs in metamorphosed strata. In Wales, Belgium, the 
Alps and France, such phenomena are frequent. The coal 
deposits of Massachusetts and Rhode Island are enclosed in 
highly metamorphosed strata. Much of the material is more 
nearly graphite than coal. Both the coal and the enclosing 
strata are so distorted that the bedding is destroyed and the 
material appears in segregated masses. 

In the trap dykes that have penetrated the sedimentary 



*Essays, pp. 301, 302. Am. Jour. Sci., 1871. 

tEssays, pp. 382, 396. W. Hodgson Ellis, "Analysis of Some Precarbon- 
iferous Coals," Chem. News, Ixxvi, 186, Oct 15, 1897. 



THE ORIGIN OF BITUMENS. 



37 



formations of the Connecticut valley and New Jersey, veins 
of carbonaceous matter occur. These dykes are intruded 
masses, no doubt formed by the igneo-aqueous fusion of sedi- 
ments that contained organic remains.* Petroleum is reported 
to have been obtained in granite in a well drilled by the Pacific 
Coast Oil Co., east of the San Fernando Pass. 

With the exception of the exudation of mineral pitch 
mentioned above, I have seen no notice that bitumen occurs 
in crystalline rocks, but always in rocks adjacent to or above 
them. There are vast areas of the palaeozoic formations of 
North America that are not crystalline, that have been more 
or less subjected to the action of steam and pressure at tem- 
peratures that have made them more or less the subjects of 
rnetamorphic action. Some of these rocks contain bitumen 
and others do not. The limestones in the bluffs of the Mis- 
sissippi River at Minneapolis and St. Paul contain in the cav- 
ities of their fossils crystals of pyrite and rhomb spar. They 
immediately overlie the St. Peter sandstone and are said to 
belong to the Trenton group. Similar limestones in southern 
Michigan contain bitumen, free sulphur and sulphates in large 
amount. In southern Kentucky and Tennessee the lime- 
stones are often coarsely crystalline and contain large encri- 
nite stems that are silicified. These same rocks contain 
geodes lined with crystals of quartz. Other geodes contain 
sulphates of barium, strontium and calcium, both with and 
without bitumen. In other localities the rocks of this age 
are filled with bitumen widely disseminated in small quanti- 
ties. These rocks often exhibit very slight evidence of the 
effects of heat, but frequently are found immediately above 
or upon crystalline schists. f 

In Prof. James Hall's celebrated Introduction to The 
Palaeontology of New York," he shows that the earliest pale- 
ozoic sediments were deposited in a current that moved from 
southeast to northwest. Later the current moved diagonally 
across them from northeast to southwest. These later cur- 
rents represent a vast interval of time, 'during which mate- 
rial accumulated to a depth of tens of thousands of feet of 



*L. C. Beck, Am. Jour. Sci. (1), xlv, 335. I. C. Russell, ibid. (3) xvi, 112. 
t3. F. Peckham, Reports of the Tenth Census of the United States, Vol. 
x. "Petroleum," p. 63. 



3 8 SOLID BITUMENS. 

coarse sediments to the northeast in Canada, and growing 
finer diminished to the southwest in the Mississippi valley to 
a few thousand feet. If metamorphic action is due to the 
accumulation of sediments, whereby the isothermal lines of 
the earth's crust rise to meet the increased pressure, by con- 
sequence of which sediments are brought into a state of 
igneo-aqueous fusion, it is not difficult to explain why, at a 
period in the earth's history, when the condition of the earth's 
crust, the ocean and the atmosphere, all contributed to main- 
tain a high temperature, the strata as we pass from the south- 
west in the Mississippi valley towards the northeast should 
present, at the surface, increasingly the effects of heat.* 

Let us now turn to technology and see what the experi- 
ence of more than half a century can teach us in relation to 
this question of the origin of bitumen. Soon after 1830, 
Reichenbach in Germany ,f Selligue in France and Gregory 
in Scotland, all worked upon the destructive distillation of 
pyroschists, wood, 4 coal, peat and petroleum. They all dis- 
covered paraffine, and what is suggestive, they all propound- 
ed the idea that bitumens are distillates. They established 
the fact that pyroschists, wood, coal, etc., when destructively 
distilled yield paraffine and the oils found in petroleum. 
Selligue established quite a valuable industry in France, using 
as his raw material the schists of Autun. About 1850, the 
Scotch paraffine-oil industry arose. The raw material was '.a 
shale, called boghead mineral, that was well known to con- 
tain fossil fishes. The distillate of this mineral closely re- 
sembled petroleum, and when petroleum was discovered in 
the United States in commercial quantities, the refineries on 
the Atlantic coast, that had been importing the boghead min- 
eral, commenced to work petroleum with slight changes in 
their processes. At the same time, the albertite of New Bruns- 
wick was also being distilled on the Atlantic coast, while west 
of the Alleghenies cannel was being distilled at Cannelton, 
on the Kanawha River, in West Virginia ; at Cloverport, on 
the Ohio River, in Kentucky; at Newark, O., and near Pitts- 
burg, Pa. The experiment of distilling oil from Devonian 

*Nat. Hist, of N. Y., "Palaeontology," iii, 45-60. 

tJour. fur Chem. u. Phys., von Schweiger-Seidel, 1830, lix, 436. Trans. 
Roy. Soc. of Edinb., xiii, 125. Rep. of Pat. Inven., n. s., iv, 109 Jour, des 
Connaisances Usuelle, Dec., 1834, p. 285. Dingier, Ivi, 4t). 



39 

pyroschists was also made at Erie, Pa. They yielded fifty 
gallons of distillate to the ton. Without exception every one 
of these materials yielded paraffine, and when the petroleum 
obtained from Pennsylvania and West Virginia was used as 
a substitute it was found that it yielded identical products, 
and the coal-oil industry was quickly rendered unprofitable. 
In an attempt to utilize all available material, William At- 
wood, who was one of the most skillful technologists in coal 
oil, w r as sent to the Island of Trinidad, where a plant was 
constructed and an unsuccessful attempt made to prepare 
illuminating and lubricating oils from Trinidad pitch. The 
pitch furnished distillates very different from- the paraffine 
products obtained in the United States. 

During the last years, before the coal-oil industry ceased 
to be profitable, a number of patents were granted for im- 
provements in this technology, mainly for improved methods 
of distillation. The aim of these inventions was to effect a 
uniform heating of the material by which a slow distillation 
at low temperatures would be promoted. The presence of 
steam, often superheated, was found to be at all times bene- 
ficial. While to produce gas from these materials, it was found 
necessary to thrust them into a retort heated to a high tem- 
perature, to produce oil, it was found, on the contrary, best 
to distill at the lowest temperature possible. The intermedi- 
ate oils, too dense for illumination and too light for lubrica- 
tion, accumulated in the refineries, until Luther Atwood dis- 
covered that by distilling them in such a manner that the 
vapors were superheated the vapors were "cracked" or "dis- 
sociated," and when they were condensed they were found to 
be of such a specific gravity that they could be used for illu- 
mination. This was the most important discovery ever made 
in the technology of bitumens, and when applied to the manu- 
facture of paraffine petroleums it was of enormous value. 

Soon after 1860, attempts \vere made to treat the bitu- 
mens of southern California by the same methods of distilla- 
tion that were employed in treating paraffine oils, but all the 
results obtained showed that the processes were being applied 
to different materials and the results were different. These 
results all pointed to an excess of carbon and more unstable 
compounds. On analysis these crude oils were found to con- 



4 o SOLID BITUMENS. 

tain a large percentage of nitrogen as compared with paraffine 
petroleums. * 

Canadian petroleum had been known to contain sulphur 
and to be difficult to refine. When similar oils were obtained 
in large quantities about 1885, in western Ohio, the sulphur 
petroleums became a serious problem in the technology of 
bitumen, as it was commercially desirable to treat them in the 
same manner as the pure paraffine petroleums of Pennsyl- 
vania. During 1893 and 1894, the technology of California 
bitumens was again investigated. Destructive distillation 
when applied to these bitumens, resulted in the production of 
a large volume of gas and asphaltic residuums with a dis- 
tillate consisting principally of unsaturated hydrocarbons. 
The crude oils were found to be allied to the crude oils pro- 
duced in the Scotch shale-oil industry, as they contain a large 
percentage of nitrogenous basic oils.f 

There were thus established among North American bitu- 
mens three great classes: those known as Pennsylvania oils, 
consisting of nearly pure paraffines, for which I have else- 
where proposed the name of Warrenite ; those known as Lima 
oil, which together with the Canadian oils contain a notable 
proportion of sulphur compounds, for which I have proposed 
the name of Maberyite, and the California oils, which occur 
in great variety and, while containing sulphur, are charac- 
terized as nitrogen bitumens and for which I have proposed 
the name of Venturaite. There is also a class of bitumens 
not yet investigated that are found on the eastern slope of the 
Rocky mountains from Mexico to the Arctic circle. In Eu- 
rope, the paraffine petroleums of Galicia appear to be quite 
distinct from the bitumens of the Caspian Sea. Technology 
has also divided bitumens into two great classes that are 
largely determined by geological occurrence. The great pe- 
troleum region of North America, which is by far the most 
important in the world, lies in the great palaeozoic basin that 
surrounds the Cincinnati anticlinal ; while the bitumens of 
California, the West Indies and Europe issue from Tertiary 
rocks. These Tertiary bitumens are found in much greater 



*S. F. Peckham, Reports Geol. Surv., California, "Geology," ii, Appen- 
dix, p. 73. 

|S. F. Peckham, Am. Jour. Sci. (3), xlviii, 250. 



THE ORIGIN OF BITUMENS. 41 

variety and are uniformly more difficult to refine into com- 
mercial articles than the bitumens obtained from older forma- 
tions.* 

It is proper to mention in this connection three classes of 
investigations that have been made on a commercial scale. 
The first was made about 1860-65, by Cyrus M. Warren, and 
consisted in distilling destructively the lime soap made from 
menhaden (fish) oil. The products of this distillation were 
refined into illuminating oil, in all respects identical with coal 
oil and refined petroleum ; and they were also proved by an 
elaborate research to contain the same constituent hydrocar- 
bons. Quite recently, Prof. Karl Engler has repeated these 
experiments with the addition of pressure and steam during 
distillation. Warren's results were confirmed. Still more re- 
cently, Dr. S. P. Sadtler has discovered that the vapors es- 
caping from linseed oil while being boiled furnish, when con- 
densed, a petroleum-like liquid, which upon examination was 
found to consist of hydrocarbons identical with those found 
in Pennsylvania petroleum. It is an honor to American sci- 
ence that these results, valuable and interesting alike to sci- 
ence and technology, were obtained by American investiga- 
tors.f 

The general conclusion from technology appears to be, 
that for commercial purposes, crude bitumens and the prod- 
ucts of their distillation may be duplicated by products of the 
destructive distillation of pyroschists, wood, coal, peat and a 
great variety of animal and vegetable substances. 

It would be entirely unnecessary for the present purpose 
to notice in detail all the researches that have been under- 
taken upon bitumen, in all its various forms, since de Saus- 
sure published his paper on the "Naphtha of Amiano," in 
1817. It is sufficient to indicate along what lines the investi- 
gations have proceeded and in what manner the results have 

*Boverton Redwood, "Petroleum," etc., London. Charles Griffin & Co.. 
1896, ii. S. F. Peckham, Proc. Am. Phil. Soc., x, 445. Repts. 10th Census, 
U. S., x, "Petroleum," Am. Jour. Sci. (3), xlviii, 250 and 389, 1, 33. Science 
xxiii, 74. Jour. Frank. Institute, Nov., 1895. S. P. Sadtler, Am. Jour. 
Pharm., Sept., 1896. C. F. Mabery, Jour. Frank. Institute, cxxxix, 401. 
Proc. Am. Acad., n. s., xxiii. Am. Chem. Jour., xix, 243, 374, 419, 796. B. 
Sillman, Jr., Am. Jour. Sci. (ii), (xliii), 242. Chem. News, xvii, 257. Bui. 
Soc. Chem. de Paris, 1868, p. 77. 

tC. M. Warren and F. H. Storer, Mem. Am. Acad. n. s., ix, 177 Karl 
Engler, Berichte der Deut. Chem. Gesellschaft, 1888, xxi, 1816. xxii, 592. 
Dingier, Poly. Jour., 1889, p. 271. S. P. Sadtler, Am. Jour. Phar., Sept., 1896. 



42 SOLID JilTi'MliXS. 

been interpreted. The earliest investigators analyzed bitu- 
mens as if they were homogeneous substances. They deter- 
mined the carbon and hydrogen, added the percentages to- 
gether and subtracted the sum from one hundred, calling the 
deficit oxygen. 'This went on for nearly fifty years. It is true 
that Prof. B. Silliman, Jr., fractionated petroleum by distilla- 
tion, and queried whether the liquids that he obtained were 
educts or products. It was not until 1863 that Schorlemmer, 
in England, and Pelouze and Cahours, in France, published 
researches that professedly separated the compounds that 
were mixed together in petroleum. They were soon followed 
by Warren and Storer in the United States, who, by a supe- 
rior method of condensation, succeeded in separating the 
hydrocarbons in coal-tar naphtha, naphtha from Pennsylvania 
and Rangoon petroleum, naphtha from lime soap of men- 
haden oil and also the hydrocarbons from oil of cumin. These 
researches established the existence in these liquids of several 
series of hydrocarbons, the members of which were identical, 
whether obtained from natural or artificial substances, and 
were also in many cases recognized as identical with chemical 
compounds already well known.* 

Since these results were published, a great amount of 
work has been done with varying success upon a great vari- 
ety of petroleums, in which work progress has been observed 
along two lines, viz., first, better methods of separation, and, 
second, better methods of ultimate analysis. It is only quite 
lately, however, that Prof. C. F. Mabery has succeeded, by 
distilling in vacuo with Warren's hot condenser, in so com- 
pletely avoiding decomposition by cracking as to reach re- 
sults that are final. While this is said without any wish to 
disparage the work of other investigators, it must be said 
with a proper regard for truth. f There is, however, a. vast 
amount of chemical research on record, a very complete 



*Theo. de Saussure, Ann. Chim. et de Phys. (2), iv. 314-320, London Jour, 
of Sci., iii, 411. B. Silliman, Jr., Am. Chemist, ii. 18. Moniteur Scientifique. 
No. 366. Am. Jour, of Gas Lighting, xvi, 83. Wagner's Ber., 1872, p. 848. 
C. Shorlemmer, Chem. News, 1863, viii. 157; xi, 255. Am. Jour. Sci. (2). 
xxxvi. 115. Rep. de Chim. Applique^. 1863. p. 174. Jour, fur Phar., xxi, 320. 
J. Pelouze and Aug. Cahours. Comptes Rendus. Ivi, 505; Ivii. 62. Ann. de 
Chim. et de Phys. (4), i, 5. Am. Jour. Sri. (2). xxxvi. 412. C. M. Warren and 
P. H. Storer. Mem. Am. Acad., n. s., ix, 121-176. Am. Jour. Sci. (2), xxxix, xl 
and xli. Chem. News, xii, 85. 261. et seq. 

tC. F. Mabery, Proc. Amer. Acad., n. s., xxiv; Amer. Chem. Jour, xix, 
243, 374, 419; Proc. Am. Phil. Soc. xlii, 36 



THE ORIGIN OP BITUMENS. 43 

resume of which can be found in the exhaustive work of 
Boverton Redwood, which has given results sufficiently accu- 
rate for our purpose. These results may be generalized as 
follows : 

The Pennsylvania petroleums are the purest paraffine 
petroleums known. They contain small percentages of ole- 
fines and traces of benzoles. The same hydrocarbons have 
been found in other petroleums, in the distillates from cannel 
coal, pyroschists, peat, wood tar, fish-oil soap, fish oil under 
pressure and linseed oil, and also from Grahamite, Albertite, 
ozocerite and many other substances of mineral and organic 
origin.* 

The Lima and Canadian petroleums contain the paraffine 
series, with a notable proportion of sulphur derivatives of the 
paraffines, formed by substitution ; and also traces of benzoles 
and nitrogenous basic oils.f 

The Russian oils contain the benzole hydrides and naph- 
thenes, with little, if any paraffin es4 

The California oils, so far as at present known, consist 
of the benzole hydrides, naphthenes, benzoles and sulphur 
substitution compounds with a large percentage of esters of 
nitrogenous basic oils, and no appreciable amount of par- 
affines. || 

The Scotch shale oils contain paraffines, defines, ben- 
zoles and esters of nitrogenous basic oils.** 

These esters are also found in coal tar and in Dippel's oil, 
the latter being an oil obtained as a distillate from the gelatine 
of bones. 

No satisfactory research has ever been undertaken upon 
semi-fluid malthas or solid asphaltums. They cannot be dis- 
tilled without decomposition, and no analysis by solution has 
yet been made that was not highly empirical. It is assumed, 
rather than proved, that many solid bitumens contain oxygen. 

*Schorlemmer, Pelouze et Cabours, Warren and Storer, Mabery, loc. cit. 

tMabery and Smith. Proc. Amer. Acad., n. s., xxiii; Amer. Chem. Jour., 
xvi, 83, 89, 544; xvii, 713; xix, 419. 

$S. F. Peckham, Proc. Amer. Phil. Soc., x, 445; xxxvi, 154; xxxvii, 108; 
Amer. Jour. Sci. (3) xlviii, 250. C. F. Mabery, Jour. Frank. Inst., cxxxix, 401; 
Proc. Am. Phil. Soc., xlii, 36. Boverton Redwood, Petroleum, i, 203. 

IIBeilstein and Kurbatow. Ber. d. D. Chem. Ges., 1880, p. 1818. Jour. Amer. 
Chem. Soc., xiii. 232. Markonikow and Oglobini, Ber. d. D. Chem. Ges., xviii, 
2284; Ann. de Chim. et de Phys. (6), ii, 372. 

**English patents. 



44 



SOLID BITUMENS. 



They certainly do contain sulphur, and in some instances they 
contain nitrogen. When distilled upon a large scale solid 
bitumens are decomposed and nothing but decomposition 
products are found in the distillate, while coke remains in the 
still. These decomposition products are very varied. Those 
that are geologically old yield paraffine, while those that are 
recent do not.* 

Prof. Mabery has remarked that all petroleums contain 
the same approximate principles in different proportion. 
While this statement may be absolutely true, it is not so rela- 
tively. The palaeozoic bitumens have been most carefully 
studied and they consist mainly of paraffines. The Tertiary 
bitumens have been less carefully studied, and they consist 
principally of benzoles and their derivatives in great variety. 
Mingled with these are the olefines and other series of hydro- 
carbons in small proportion, with an immense number of 
oxygen, sulphur and nitrogen derivatives and substitution 
compounds, the existence of which has been only recently 
suspected. 

It can, therefore, be asserted that the natural bitumens 
and the substances resembling them that are obtained by the 
destructive distillation of mineral and organic substances, are 
strikingly similar. The palaeozoic bitumens bear a re- 
semblance to the simple distillates produced in the presence of 
steam, at low temperatures, when nitrogen is practically ab- 
sent. The Tertiary bitumens resemble the distillates obtained 
at higher temperatures and when the raw material is rich in 
animal remains. There are, however, a large number of bitu- 
mens that have been too little investigated to admit of any 
generalizations concerning them. In illustration of this state- 
ment, attention is called to the valuable papers of Prof. Henry 
Wurtz, in which he shows that many so-called native par- 
affines are probably olefines. f The author suggests that some 
of them may be the higher naphthenes, that have the same 
percentage composition as olefines. The solution of these 
problems awaits a vast amount of research. 

In the preceding pages I have given an outline of the 

*S. F. Peckham and L. A. Linton. Amer. Jour. Sci. (4), I, 193. S. F. and 
H. E. Peckham, Jour. Soc. Chem. Industry, xvi, 424; H. Endemann. ibid, xv, 
871; xvi, 121. 

fH. Wurtz, EYig. and Min. Jour., xlviii, 25, 114; li, 326, 376. 



THE ORIGIN OF BITUMENS. 



45 



views generally held by chemical and physical geologists con- 
cerning the chemical phenomena attending the cooling of the 
earth and its shrinking and contracting crust. To these I have 
added a resume of the technical and chemical knowledge we 
possess concerning bitumens. I shall now proceed to discuss, 
in the light of these facts, the occurrence of bitumens and the 
relation of such occurrence to their probable origin. 

Leaving the problems of orography to the physical geolo- 
gist for solution, there are a few suggestions to be made relat- 
ing to these problems, that I have not seen anywhere men- 
tioned. If we regard the dizzy heights of the Andes and 
Himalayas, 'or the profound abysmal depths of the Pacific as 
isolated phenomena, they appear on a scale of oppressive 
grandeur and immensity ; yet these irregularities in the earth's 
crust reach a maximum of only about ten miles in vertical 
height, which is only one twenty-five hundredth or four hun- 
dredths per cent, of the circumference of the earth at the 
equator. The local foldings of a few hundreds of feet in dis- 
turbed strata are microscopic when compared with the earth's 
diameter; and yet we are accustomed to regard these plica- 
tions of strata as the result of sudden movements in the 
earth's crust. This is a pure assumption. The period 
of time through which critical observations of geological phe- 
nomena have been made when compared with the time that 
has elapsed since life dawned upon the earth is also micro- 
scopic; it is a smaller fraction than four hundredths per cent. 
The element of time in geological phenomena is only just be- 
ginning to be appreciated. We have learned from a few years 
of observation that some continental masses are rising and 
others falling with reference to the sea level ; yet no one has 
observed these movements through many centuries, nor 
have these vertical movements of the coasts of the world been 
correlated and the laws that govern such movements been 
determined. We do not know whether a continent has 
emerged from an ocean maintaining a constant level, or 
whether the ocean has receded as the contracting mass has 
rendered the ocean depths more profound, or, as is more prob- 
able, the shrinkage of the crust has changed the distance of 
the ocean surface from the center of the earth, rendering the 
elevations apparently greater. It is not material to this ques- 



46 SOLID BITUMENS. 

tion that we should know. Nor is it of importance to consider 
whether the continued operation of forces at present active 
through countless centuries, or the repeated interjection of 
catacylsms of world disaster, has brought the earth to its pres- 
ent condition. Volcanic eruptions, earthquakes and floods, 
separately and unitedly, change the face of nature within our 
own generation ; it is reasonable to suppose that they have act- 
ed from the earliest period of the earth's history to the present 
time with constantly lessening violence. It is true that the local 
effects of such phenomena as the earthquakes at Lisbon and 
Java and the Red River fault appear cataclysmic ; yet these ef- 
fects are microscopic when compared with the dimensions of 
the earth, and may have been, nay, probably were the culmina- 
tion of a series of movements that had been in progress for 
immense intervals of time. I therefore believe that in stating 
the causes of those changes that have taken place at the sur- 
face of the earth as we know it, one of the most important 
considerations is the unlimited periods of time through which 
the pressure due to accumulation of sediments and the conse- 
quent development of heat has acted upon those sediments, 
which in many instances were rilled with water charged with 
mineral matter in solution. From the combined action of 
pressure, heat and steam, through unlimited periods of time, 
the constituent elements of sediments have been brought into 
every possible state of combination, from obsidian and 
pumice, which have been completely fused, through lavas, 
granites, gneisses, etc., to sediments in which there has been 
no change at all. As Dr. Hunt has fully shown, the action of 
thermal waters, which have been largely instrumental in pro- 
ducing these changes, has been often extremely localized, both 
laterally and vertically, and may be greatly varied by the con- 
stituents of the sediments themselves. 

If then, we accept the hypothesis that all of the rocks as 
we now know them are sediments, whatever may be their 
present condition, we are forced to the conclusion that life 
first appeared upon the planet at a date too remote to be 
determined even in geologic time, and that the remains of 
organic forms have practically been a constant constituent of 
sediments from that time to the present. As might be ex- 
pected, we find organic remains in every possible condition, 



Tllll ORIGIN OF BITUMENS. 47 

from crystallized graphite to unaltered cellulose. Vegetable 
and animal remains are found in every conceivable condition 
of replacement and alteration. We find pseudomorphism in 
the strictest sense as well as metamorphic action developed in 
every possible degree. Nor can we assert that any of the 
older strata are free from such action, for metamorphism is, 
as the word signifies, a change of form, and no limits can be 
assigned to such change in either time, place or degree that 
are not arbitrary. There can be no question that as sediments 
have accumulated slowly so these changes have progressed 
slowly. 

Nevertheless, following upon long periods of quiet, there 
appear to have been periods of cataclysmic violence, as when 
the vast lava sheets that form the table mountain of the Sierra 
Nevada were poured out, not from a single peak, but from a 
whole range of peaks ; when the whole of southern Colorado 
and northern New Mexico and Arizona were covered with 
lava sheets thousands of square miles in extent ; or when the 
valleys "of West Virginia were upheaved, the Oil Break formed 
and the mass of plastic Grahamite forced into the fracture; or 
when the basic rocks that form the mounds of iron porphyry 
in Cumberland and Foster, R. I., were thrust up from the 
deeps ; and the trap dykes along the whole eastern borders of 
the Alleghanies were poured into fractures of local extent ; 
or when the veins of Gilsonite and allied bitumens were 
poured into fractures in a plastic condition in Utah. But 
these convulsions that have brought basic porphyrys, basalts, 
trap dykes and local metamorphism to the surface, have in 
the physical and chemical operations of nature produced an- 
thracites and anthracitic residues and not bitumens. Bitumens 
are not the product of the violence of volcanic or cataclysmic 
action, but of the gentler action of normal metamorphism ex- 
erted through long periods, during which the volatile bitumen 
has been distilled from sediments containing organic matter, 
and at the lowest possible temperature, without regard to 
time, as the sediments were pressed down to an isothermal 
that admitted first of their distillation and then of the conver- 
sion of the carbon residues into graphite. 

Dr. Hunt has left hundreds of pages in which he has 
shown that the crystalline and eruptive rocks, as we know 



48 SOLID 

them, are altered sediments. His argument is conclusive that 
the carbon that they contain is derived from organic forms. 
When discussing bitumens he shows, first, that the pyro- 
schists do not, except in rare instances, contain bitumen, and 
are not in the proper sense of the word bituminous. Sec- 
ondly, he shows that the pyroschists do not, "whether ex- 
posed at the surface or brought up by boring from depths of 
many hundred feet, present any evidence of having been sub- 
mitted to the temperature required for the generation of vola- 
tile hydrocarbons." Thirdly, he shows that as the oil occurs 
in the limestone it could not have been distilled. He further 
shows that the Utica slate that is beneath the lower Devonian 
limestones is unaltered, and adds, "More than this, the Tren- 
ton limestone, w r hich on Lake Huron and elsewhere has 
yielded considerable quantities of petroleum, has no pyro- 
schists beneath it, but on Lake Huron rests on ancient crys- 
talline rocks with the intervention only of a sandstone devoid 
of organic or carbonaceous matter.* 

I have already shown that sediments become crystalline 
at very low temperatures and that the crystalline schists be- 
low the lowest stratified rocks contain abundant evidences of 
organic forms. Are we to suppose that there was no inter- 
mediate zone in which normal metamorphism died out and 
faded into unaltered sediments? We ought to expect to find 
the pyroschists in their normal condition. We ought to expect 
to find the coal altered or unaltered, according to its proximity 
to the heated area. We should not expect to find the carbon- 
ized remains of organic forms in rocks containing bitumen ; 
for we cannot suppose that those beds that yielded the bitu- 
men by distillation were suddenly plunged into a condition of 
igneo-aqueous fusion by which the organic constituents were 
instantly converted into anthracite and gas. As a general 
rule the process of conversion must have been as gradual as 
the progress of deposition. We cannot assume that in every 
instance the anthracite is the residue from a distillation of 
which the distillate was completely lost. Moreover, the ex- 
ample cited above, of observations in southern California, is 
a complete demonstration, occurring as it does in a region 

*T. S. Hunt, Essays, p. 169, ed. 3875 



THE ORIGIN OF BITUMENS, 49 

rich in bitumen, that the change from sediments to crystalline 
schists is progressive and involves the organic as well as min- 
eral constituents of the strata. 

If a traveler should leave Boston, Mass., and travel in a 
generally southwest direction toward San Diego, in southern 
California, he would encounter along his route a series of 
object lessons that would lead to but one conclusion. What- 
ever the age of the crystalline rocks of New England may be, 
they are certainly for the most part older than the Carbonifer- 
ous. The small basin around Mansfield, Mass., extending 
into Rhode Island, which contains the anthracites of that re- 
gion, is surrounded by crystalline rocks, and, indeed, the 
anthracite beds themselves are, as already stated, altered to a 
substance nearer graphite than coal. The coal slates contain 
only impressions of coal plants, and fossils of any description 
are extremely rare in the vicinity. Intrusions of trap are fre- 
quent, and cones of highly basic porphyries are thrust up 
through all of the crystalline sediments at several points. The 
change of form has been very complete in respect to every 
constituent of the sediments. 

Westward around New Haven, Conn., the bedding of the 
sediments has not been so completely obliterated, but the 
change in the organic constituents has been quite as general. 
In the gneissoid traps of that region, thin veins of anthracitic 
material occur, which alone remain to represent the organic 
constituents of the altered sediments. Continuing our course 
southwestward the same changed condition is observed in 
the crystalline schists of Manhattan Island, and across the 
Hudson through northern New Jersey. Intrusions of trap, 
too, are frequent through all this region and the sole repre- 
sentative of the organic constituents of the sediments is an- 
thracitic residues. 

On the western slope of the Catskills, through eastern 
New York, the crystalline rocks which exist at varying depths 
below the surface are overlaid with sediments which are fre- 
quently imperfectly metamorphosed, and as one moves west- 
ward into central New York and northeastern Pennsylvania, 
while the coal beneath the surface is anthracite and the resi- 
dues before mentioned that fill cavities in the limestone are 
anthracitic, still the surface rocks show less and less signs of 



5 o SOLID BITUMENS. 

alteration. As the summit of the Alleghanies is reached and 
passed, the coal beds fade by insensible stages from anthracite 
into unaltered splint and cannel coals. The beds of slate also 
become beds of pyroschists, and the formations generally as- 
sume the aspect of unaltered sediments. On the western 
slope of the Alleghanies the surface descends much less ab- 
ruptly than it ascends on the eastern slope. . The dip of the 
formations is much greater than that of the surface, conse- 
quently the outcropping edges of newer formations are re- 
peatedly encountered, until in western Pennsylvania and New 
York metamorphism has ceased to be a problem in surface 
geology. These surface rocks are, however, geologically all 
below the coal, which in eastern Pennsylvania is metamor- 
phosed into anthracite. There is no arbitrary line that sep- 
arates the unaltered from the altered strata. The successive 
formations have thinned out, and in general they continue to 
become thinner as we go southwest ; but there is no anthra- 
cite between the crest of the Alleghanies and the mountains 
of Arkansas. Throughout the Mississippi valley, as we pass 
to the west, these formations outcrop and overlie each other 
precisely like the shingles on a roof, with the pitch reversed. 
In the Bradford oil fields, in McKean County, Pa., the 
drill penetrates a bed of porous sandstone that lies enclosed in 
impervious unaltered strata. It contains a few shells and fish 
bones, but no other fossils. Like the surface rocks it lies 
sloping toward the southwest, the lower portion submerged 
in salt water, the middle portion filled with petroleum and 
the upper portion filled with gas, both originally under an 
enormous pressure. In Warren County, farther to the south- 
west, the drill reaches petroleum not in the McKean County 
sand, but in a different sand, higher in the series. Still farther 
southwest, in Venango County, the surface rocks are still 
higher in the series and the drill reaches petroleum in a pebble 
conglomerate that outcrops at the surface to the northeast. 
These pebble conglomerates, known as the "Venango Oil 
Sands," formed great riffles in the currents of the primeval 
ocean. They are several miles long and a few rods wide, level 
on the upper surface, and rounded on the under surface to a 
feather edge at the sides. One is above the other and they 
are covered, when they contain petroleum, with a solid, im- 



THE ORIGIN OF BITUMENS. 51 

pervious shell of silica, that the drill penetrates with difficulty. 
The uppermost of these conglomerates consists of spherical 
pebbles of yellow quartz, about as large as cranberries ; the 
lowest consists of lenticular pebbles of very white quartz. In 
both cases the pebbles are cemented together at their points 
of contact leaving large open spaces. These conglomerates 
are sometimes replaced by coarse, porous sandstones; neither 
of these contain fossils of any kind. Still farther southwest, 
on Slippery Rock Creek in Mercer County, and at Smith's 
Ferry in Beaver County, another sandstone the Berea Grit 
that is barren where it occurs in Venango County, yields pe- 
troleum above the pebble conglomerate. If a line be followed 
farther to the left, across western Pennsylvania and into West 
Virginia, the outcrops of the formations would rise succes- 
sively in the scale until the oil would be found in the Mahon- 
ing sandstone, which lies at the top of the lower productive 
coal measures. Since the development of the Lima oil fields 
the range of rocks holding the petroleum reaches in Ohio, 
Canada and Pennsylvania from the Lower Silurian, Trenton 
limestone, to the lower coal measures. These rocks embrace 
nearly the entire palaeozoic formations of North America. 
Very few wells have been sunk below the petroleum-bearing 
sandstone, for the obvious reason that it involved a useless 
expense. One of the deepest wells ever drilled in the oil re- 
gion of western Pennsylvania was Jonathan Watson's deep 
well near Titusville. This well went down through all of the 
oil sands and the Devonian shales beneath them, to a depth 
of 3,553 feet, when just as it was abandoned a hard rock was 
struck which was supposed to be the corniferous limestone, 
which is the oil-bearing rock of Canada. The interval be- 
tween the oil sands and the bottom of the well was filled with 
Devonian shales, that underlie the Bradford oil sand and are 
supposed to extend from Allegheny County, New York, to 
central Kentucky and in fact to underlie the entire petroleum 
region that produces Warrenite the pure paraffine petrol- 
eums. When "dry" or unproductive holes are drilled outside 
the productive areas, they pass, at the horizon of the oil sands, 
through a different rock, which is compact and incapable of 
holding petroleum. These underlying Devonian shales out- 
crop at Erie, Pa., and furnish there the material that on dis- 



52 SOLID BITUMEXS. 

tillation yielded fifty gallons of distillate to the ton. Where 
this formation outcrops it is filled with fucoids and has yielded 
small petroleum and gas wells. The men who drilled Jona- 
than Watson's deep well stated that "the soap stone (De- 
vonian shale) became harder as they went down, and was 
redder in color, in fact, had been burnt like brick." In a com- 
paratively few localities, petroleum has been found saturating 
rocks that lie one above the other. The upper rock invariably 
yields the most dense oil. In 1881 I saw a well in West Vir- 
ginia, from which the same walking beam pumped at every 
stroke oil of 27 from a depth of 255 ft. and oil of 45 from a 
depth of 600 to 700 ft. 

I have never seen a specimen of graphite reported to have 
come from any locality between the crest of the Alleghanies 
and the Ozark uplift. This is an uplift of the palaeozoic for- 
mation west of the Mississippi River, extending from central 
Missouri to central Texas. It resembles that of the Alle- 
ghanies, but is on a smaller scale.* The eastern slope is more 
abrupt than the western. The formations of the central por- 
tions, in Arkansas and Oklahoma, are highly crys- 
talline, and graphite and anthracite are of frequent occurrence 
and are found on the western slope. On this slope also, but 
farther west, in unaltered strata immediately above the crys- 
talline formations, bitumen occurs in enormous quantity and 
great variety. Over a large area in the northeastern portion of 
Oklahoma heavy petroleums are found only a short 
distance beneath the surface, and, as I am informed, below the 
coal. South of the Red River, in northern Texas, bitumens 
occur saturating horizontal beds of sand that are intercalated 
between strata of more or less solid limestone. North of the 
Red River, in Oklahoma, every rock formation that is 
at all porous appears to be filled with bitumen. As far as 
I have investigated it, the bitumen is uniform in kind and 
quality. It has saturated beds of sand, strata of sandstone and 
limestone, some of which are hard and crystalline, others mag- 
nesian and almost as soft as chalk, some of them without fos- 
sils, and some almost all fossils, and all of them conformable 
with the Upper Silurian and Lower Carboniferous rocks that 

*J. C. Branner, "Former Extension of the Appalachians Across Mississip- 
pi, Louisiana and Texas," Am. Jour. Sci. (4) iv, 357. 



THE ORIGIN OF BITUMENS. 



53 



enclose them. In one locality a sort of bituminous breccia 
occurs, of immense extent, consisting of fragments of lime- 
stone and quartzite cemented together with bitumen. In an- 
other an immense horizontal bed of sand, completely saturated 
with bitumen, is overlaid with 30 or 40 ft. of conglomerate 
that has been more or less penetrated with it. 

Many of the beds north of the river are in very sharp 
folds that bring the strata to the surface nearly vertical, in 
eroded anticlinals that extend across the country in parallel 
lines, often many miles in length. What is of especial interest 
in this connection is the occurrence in the vertical limestones 
and sandstones of imperfectly saturated strata. The bedding 
varies from the thickness of paper to a few inches. The rock 
mass was usually most easily penetrated along the lines of 
the thinnest beds. Fractures which cross all these beds, in- 
cluding both the thin and thick ones, show the bitumen com- 
pletely filling the thin beds and only partially penetrating the 
seams and the mass of the thicker cryptocrystalline strata. 
Nothing could more beautifully and clearly demonstrate the 
fact that the bitumen was not indigenous to these rocks, but 
had penetrated them while previously and as at present in 
their nearly vertical position. 

Continuing our journey across the continent, bitumen is 
frequently encountered in positions contiguous to normal or 
local metamorphism, until we descend into the great valley of 
California, west of the Sierra Nevadas. Here the development 
of bitumen has proceeded on a scale of vast magnitude. On 
the western slope of the Sierras the region around Roseville, 
in Placer County, and the vicinity of the city of Stockton, are 
well known to be rich in natural gas.* There are localities 
on these slopes that have also furnished petroleum, but, as 
before stated, the bitumen deposits of California are princi- 
pally found in the Coast Ranges, and the great interior valley, 
including the ocean area lying between the Santa Barbara 
islands and the main land. The richest deposits have been 
found in Ventura, Kern and Los Angeles Counties, on the 
border line that separates the Cretaceous from the Lower Mi- 
ocene. None of the bitumen is found in crystalline rocks (un- 

*W. L. Watts, "The Gas and Petroleum Formations of the Central Val- 
ley of California," 1894. 



54 SOLID BITUMENS. 

less in the single instance mentioned above) ; yet the evi- 
dences of both normal and local metamorphism, in strata 
not far distant from the bitumen-bearing rocks, are abundant. 
The late Prof. Eli W. Blake, Jr., once visited the Santa 
Barbara islands and afterwards described to me the cascades of 
lava that had descended from the volcanic cones in the center 
of the islands over precipices into the sea. Bitumen has ex- 
uded for more than a century from the unaltered strata, whose 
upturned edges form the bed of the ocean, between these isl- 
ands and the main land. The Tertiary formations that con- 
stitute the bluffs of the coast east and west of Santa Barbara 
contain deposits of bitumen of enormous extent, and exhibit 
evidences of metamorphic action still in progress. Almost* 
every large bluff from Point Conception to San Diego con- 
tains a solfatera, the action of which leaves the Miocene 
shales, originally rich in organic matter, devoid of a trace of 
carbon. 

The best petroleum wells of Ventura County lie in the 
canons of the Sulphur mountain, one of the foothills of the 
Coast Ranges. Other wells are similarly located with refer- 
ence to these ranges. * None of them have penetrated crys- 
talline rocks ; yet the core of the Coast Ranges only a few 
miles east of the wells of the Pacific Coast Oil Co., as Dr. 
Goodale and myself found, is granite. Fragments of crystal- 
line rocks are washed out of many of the large canons that 
head in the main Coast Range back of the foothills in which 
the oil weiis are drilled. Deep drilling is extremely difficult 
in this region on account of the fragile character of the rocks. 
It might be impossible to carry a well down through all the 
bituminous strata to the crystalline rocks, but the fact that 
they are altered Miocene sediments and exist at a compara- 
tively short distance below the surface does not admit of any 
question. The evidences of metamorphism, through the 
agency of hot, silicated water, are found everywhere. The 
formations contain abundant remains of highly organized ani- 
mals; and the bitumens which they contain consist of benzoles 
and naphthenes, without an "appreciable amount of paraf- 
fines, if any."f They also contain sulphur and nitrogen. They 

*S. F. Peckham, Mineral Resources of the United States, "Petroleum in 
California," 1894. 

fLetter of C. F. Mabery to S. F. P. 



THE ORIGIN OF BITUMENS. 55 

are evidently the products of the distillation of highly organ- 
ized animal tissue, as an effect of the accumulation of sedi- 
ments, and of metamorphic action upon unaltered sediments, 
through granite and gneiss to lava and pumice. 

If we turn from North America to Europe-Asia, the testi- 
mony of the most eminent observers seems equally convinc- 
ing. Daubree was satisfied that the origin of the bitumen 
was found in metamorphism. Other French chemical geolo- 
gists were equally w r ell-grounded in this belief. As early as 
1835, M. Rozet read a paper before the Societe Geologique de 
France in which he discussed the occurrence of asphaltic lime- 
stone at Pyrimont. He says, "The bituminous matter is found 
equally in the calcareous rock and the molass that covers it. 
It is evident that the action introducing it into the two rocks 
is posterior to the deposition of the latter. The manner in 
which it is distributed in great masses, which throw their 
ramifications in all directions, joined in such a manner that 
the superior portions generally contain less bitumen than the 
remainder of the mass, indicates that the bitumen has been 

sublimed from the depths of the globe It may be 

objected that such basaltic rocks do not appear in all the ex- 
tent of the Jura. To that I reply that they are found in the 
neighborhood, in Burgundy and in the Vosges and further, 
that in the changes in the surface of the soil, whether occa- 
sioned by fractures or by the disengagemenfT of vapors, the 
plutonic rocks do not necessarily appear at the surface. Per- 
haps in the deep valleys of the Jura the basalts are of very 

slight depth In the Val de Travers, near Neuf- 

chatel, similar phenomena are observed."* 

In 1846, S. W. Pratt associated the occurrence of bitumen 
at Bastennes with the eruption of ophite in the Pyrenees.f 
In 1854, Parran remarks concerning the occurrence of bitu- 
men in the environs of Alais, "whatever be the origin of these 
substances, whether they be due to interior emanations from 
fissures of dislocation or to circumstances exterior and atmos- 
pheric, it is evident that there was during the Tertiary period 
an asphaltic epoch in relation to which it is convenient to 
recall the numerous eruptions of trachytes and basalts which 

*Bull. Geol. Soc. de France (1), vii, 138. 
tQuar. Jour. Geol. Soc., ii, 80. 



5 6 SOLID BITUMENS. 

characterize that period, and have probably acted by distilla- 
tion upon masses of combustibles hidden in the bosom of the 
earth."* The anthracites of the Alps offer convincing proof 
that large amounts of organic matter have been involved in 
the metamorphic action that has prevailed in that region. In 
like manner the relation of the bituminous deposits of Galicia 
and Roumania to the crystalline rocks of those countries show 
the part that metamorphism has played in their occurrence. 

No theory that refers the origin of the bitumen to any 
physical or chemical action that has prevailed on a cosmic 
scale can satisfactorily explain the differences that exist in 
crude bitumens. Mr. Phillips has added the testimony of 
chemistry itself to show the improbability of a chemical origin 
for bitumens on a cosmic scale. Dr. David T. Day has shown 
the reasonableness of an hypothesis which regards the bitu- 
mens of Pennsylvania as distillates, but his idea that the vari- 
ation in the petroleums of that region is due to the effect of 
filtration is, in my judgment, hardly tenable. In Pennsyl- 
vania the darkest and heaviest oils are nearest the surface. 
The sulphur content of bitumen is too wide a subject to dis- 
cuss here in detail ; yet it may be said in general that sulphur 
enters bitumens by a secondary reaction between the bitumen 
and the sulphates dissolved in natural waters. The freedom 
of Pennsylvania petroleum from sulphur has already been 
shown to be due to the absence of sulphates in the natural 
waters of the region in which they occur. As has already 
been stated, Prof. Mabery has shown that the sulphur com- 
pounds found in Lima oil are sulpho-parafnnes. This would 
naturally follow the reduction of sulphates by paraffines, the 
reaction being a double decomposition in which sulphur is 
substituted for hydrogen in the paraffin e. Filtration would 
not be likely to remove such compounds from solution in the 
other constituents of the petroleum. 

In his discussion of the "Occurrence of Petroleum in the 
Cavities of Fossils," Mr. Phillips has offered some ingenious 
but wholly unnecessary suggestions to account for the pres- 
ence of a nearly solid bitumen in the cells of a coral reef un- 
covered in a quarry. Petroleum occurs in the rocks of the oil 

*Ann. des Mines (5), iv, 334. 



THE ORIGIN OF BITUMENS. 



57 



regions filling- cavities of every description. Geodes, fossils, 
sandstones, pebble conglomerates, porous limestones, the Chi- 
cago dolomite, gravel, anything and everything that has a 
cavity or a pore, has been found saturated with it. Why? 
Simply because the enormous pressure under which the bitu- 
men has accumlated in the crust of the earth has forced it 
there. When it has entered cavities like those in the coral reef 
described by Mr. Phillips, the diminished pressure and evapo- 
ration have resulted in the escape of the most volatile con- 
stituents. When the reservoir of the Bradford field was first 
penetrated, the pressure was estimated at 4,000 Ibs. per sq. in. 
Whether or not this estimate was approximately correct, the 
pressure was sufficient to throw the well casing and piping out 
over the top of a derrick and land it in a meadow near by. A 
short time after the famous Karg well was struck near Find- 
lay, O., I, myself, saw a pressure gage register 450 Ibs. per 
sq. in. Burning gas wells in western Pennsylvania sent 
streams of flame into the air 80 ft. in height. Notwithstanding 
this accumulation of the facts of experience during many 
years, writers still ignore the tremendous significance of such 
phenomena, and speak of these deposits of bitumen as if they 
resembled a turn-over or an apple-dumpling laid away by na- 
ture. Gas cannot have been held under such tremendous pres- 
sure through cycles of geologic time in reservoirs of porous 
rocks, from which it has been filtering, as suggested by Mr. 
Phillips. 

The complete inadequacy of all these arguments was never 
more fully set forth than in the language used by Mr. Phillips : 
"The movement of the oil through the rock displaced from 
the interstices in which it had originally collected would have 
been accelerated as the transition from solid organic tissues to 
liquid had been advanced." The decomposition of organic 
matter in situ could never have occurred under any conditions 
of accelerated pressure of even moderate amount. Action and 
reaction being equal the rocks must have been consolidated 
and capable of resisting pressure before the pressure could ac- 
cumulate. These facts are themselves the strongest reason 
for belief that the bitumens were never formed in situ in the 
porous rocks that contain them, but were gradually accumu- 
lated in those porous rocks that had been previously overlaid 



58 SOLID BITUMENS. 

with impervious strata capable of resisting the enormous pres- 
sure until the reservoirs were penetrated by the drill. The 
fact that in the limestone some fossil cavities are filled while 
others are empty lies in the further fact, that the lines of 
shrinkage and other fractures penetrated some of the fossil 
cavities while others remained intact. 

Upon this hypothesis, that bitumens are distillates, all of 
the variations observed in bitumens of different geological ages 
are easily explained. The earliest forms of animal and vege- 
table life are admitted to have been nearly destitute of ni- 
trogen ; hence when these forms accumulated in sediments, 
which, borne down by deposits above them, invaded an iso- 
thermal that admitted of their distillation, they must have 
been distilled, in the presence of steam, at the lowest possible 
temperature ; they must have been distilled under a gradually 
increasing pressure, the extent of which depended upon the 
porosity of the sediments above them, up to the surface. They 
must also have been distilled under a gradually increasing 
temperature which would have been largely controlled by the 
pressure. While the temperature and the pressure would have 
in every instance been the least possible, with steam always 
present, these physical conditions would on account of the 
varying porosity and consequent varying resistance of the 
overlying mass have produced very great effects in some in- 
stances and very slight effects in others. As a consequence, 
we have in natural bitumens, as in artificial distillates, mate- 
rials varying in density from natural gas to solid asphaltum. 

If these distillates proceeded from materials that would 
yield parafifine, these permanent and stable compounds, from 
marsh gas to solid parafBne, remained in the receptacles that 
nature had provided for them until they were released by the 
drill. If, however, the distillates proceeded from sediments 
of a different geological age, containing animal and vegetable 
remains more highly organized, that would yield different 
series of hydrocarbons, with compounds of nitrogen, then a 
very different bitumen would be stored in these receptacles. 
Secondary reactions would convert these primary distillates 
into a great variety of substances. The contents of the 
original reservoirs, borne down and invaded by heat, might 
become involved in a second distillation at an increased pres- 



THLL OIUGL\ Ol' BITUMENS. 59 

sure and temperature. Fractures of these reservoirs from 
excessive pressure might lead their contents to the surface 
along lines of contact of strata or with water containing sul- 
phates by which an originally pure hydrocarbon would be 
converted into a sulphur bitumen. A nitro hydrocarbon, 
reaching the surface under these conditions, might, by the 
combined action of evaporation and reaction with sulphates, 
pass through all the varying degrees of density from petro- 
leum to maltha and become finally solid asphaltum, and this 
through the lapse of time and abundance of material on a 
scale of vast magnitude. 

Such, then, is the "Testimony of the Rocks," along a line 
which spans the western continent. Nearly the whole of this 
line has been brought under my own personal observation. 
There is also reason for believing that a line might be fol- 
lowed in the eastern continent from the North Sea to Java 
that would furnish equally convincing proof. To this testi- 
mony is added that of chemistry, technology, mineralogy, and 
the chemistry of the cooling earth. Each supports and cor- 
roborates the other. We have no need to search for coke 
until we know that coke was formed. We have no need to 
assume, that in the laboratory of Nature high temperatures 
and rapid action were necessary to produce results, for which 
infinite periods of time and the lowest possible temperature 
were fully adequate. 

Dr. Edward Orton read at Montreal, December 28, 1897, 
an address in which the author notes two very important ob- 
servations. In speaking of MendeljefFs chemical hypothesis, 
"It is hard, therefore, to see why, the whole world over, pe- 
troleum is entirely wanting in the Archean and exclusively 
confined to the stratified rocks. There is not an oil field in 
the world in rocks of Archean time." I pass this by without 
comment to notice his observation upon the gas wells drilled 
in Oswego and Onondaga Counties, N. Y., one of which pene- 
trated a limestone that was found between the Potsdam sand- 
stone and granite, and furnished a gas pressure of 340 Ibs. ; 
the other at a depth of 120 ft., in the Trenton limestone, gave 
the gas pressure of 1,525 Ibs. Dr. Orton well says, "A rock 
pressure of 1,500 Ibs. per sq. in. stands for, nay demands, a 
hermetic seal." Speaking of the Potsdam sandstone and the 



60 SOLID BITUMENS. 

dark limestone beneath it, he says, "The drillings brought 
from these horizons seem normal in every respect. Certainly 
there is no hint of any transformation by heat. The smell of 
fire has not passed on them.' There is no carbon residue. 
The bituminous products found in them cannot owe their 
origin to the usual form of destructive distillation.''* It is 
not likely that the usual form of destructive distillation as il- 
lustrated in a gas retort has obtained anywhere in the opera- 
tions of nature. I regard the penetration of granite beneath 
bitumen-bearing rocks as a most conclusive and unexpected 
support to the validity of the views herein set forth. The 
longer I study the subject and the wider my experience be- 
comes, the less I am prepared to assert that any formula is 
capable of universal application. I would therefore suggest, 
that, as we now find them, bitumens are in some instances 
still where they were originally produced by a process of 
decomposition of animal remains, that is at present being il- 
lustrated on a small scale in the shallow bays of the Red Sea. 
Further, that other deposits contain primary distillates from 
the vegetable and animal remains enclosed in geological for- 
mations that have been invaded by heat, steam and pressure 
in past periods of the earth's history ; and finally, that in some 
instances, as we now know them, bitumens have been trans- 
fered and stored by a secondary invasion of bituminous de- 
posits by heat, steam and pressure. The details of these 
various movements await for their expression a vast amount 
of chemical and geological research by those who are to come 
after us. 

I have quoted thus fully from Dr. T. Sterry Hunt for two 
reasons ; with all his eccentricities, he was a man of untiring 
industry and a profound interpreter of the phenomena of na- 
ture in the light of experiment. Therefore, no writer of recent 
years has expressed views that are entitled to more respectful 
consideration. He is also more widely quoted by both Ameri- 
can and European writers upon the subject of the origin of 
bitumens, especially as an exponent of the doctrine that bitu- 
mens are indigenous to the rocks in which they are found, 
than any other author.f 

*Bul. Geol. Soc. America, ix, 03. 

fProc. Amer. Philos. Soc., vol. xxxvi, 103; vol. xxxvii, 108. 



THE ORIGIN OF BITUMENS. 6l 

This discussion is directed mainly to the origin of petro- 
leum. It applies with equal force to all primary forms of bitu- 
men, whether gaseous, liquid, semiliquid or solid. The evi- 
dence is constantly accumulating where bitumens occur in all 
parts of the world. In Texas the petroleum occurs in sands 
that are interstratified with strata that contain at a depth of 
only 1,200 ft., warm artesian water. During a recent visit 
to New Brunswick the author learned that anthracite had 
been discovered in the western extremity of the range of hills 
in which the Albertite occurs, and that petroleum had been 
obtained from wells drilled at a point lying between them. 
The entire region is a region of metamorphic rocks, changed 
through the action of hot silicated water. 

The origin of bitumens cannot be established in labora- 
tories, but must be wrought out as the result of a careful 
comparison of the operations of technology with the opera- 
tions of nature, into which time has always entered in suf- 
ficient quantity. 



CHAPTER III. 

THE CLASSIFICATION OF BITUMINOUS SUB- 
STANCES. 

A correct classification of bituminous substances divides 
them into three classes, viz. : bitumens, pyrobitumens and 
factitious or artificial bitumens. 

The first 'embraces those natural substances defined by 
numerous authorities as consisting principally of carbon and 
hydrogen, and occurring under gaseous, fluid and solid forms 
as natural gas, petroleum, maltha, and asphaltum or asphalt, 
sometimes pure and sometimes mixed in varying proportions 
with other substances. They occur in outflows, saturating 
beds and masses of rock and in true veins into which the solid 
forms have been injected in a plastic condition. They are 
more or less soluble in various neutral liquids, but particu- 
larly in chloroform and bi-sulphide of carbon. They are 
usually black in mass and bfown in powder or solution, and 
are very inflammable. 

In one of the earlier papers of Dr. T. Sterry Hunt it is 
shown that certain relations exist between coal and bitumens. 
Dr. Hunt read a paper at Terre Haute, Ind., in 1870, on the 
"Oil-bearing Limestone of Chicago," and later papers, in 
which he makes clear the distinction between minerals that 
are true bitumens, soluble in chloroform and bi-sulphide of 
carbon, and minerals that are insoluble in those liquids, but 
which yield, when distilled, substances that resemble bitu- 
mens in physical properties. These he called pyro-schists, 
and pyro-bitumens. This distinction he deemed of great im- 
portance, as it really is, and he enforced it with all the energy 
of which he had no lack. All coals, except anthracite, yield 
bituminous products on distillation. Besides the coals, there 
are deposits of carbonaceous minerals in great variety of form 
and degrees of purity that are known in mineralogy as bitu- 
minous schists and shales that also yield bituminous distil- 
lates. These are properly referable to the second class. 

62 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 63 

To the third class are referable an immense number of 
substances, most of which are by-products of manufacture, 
but some of which are direct products of the arts. They are 
properly divided into three groups, one of which consists for 
the most part of educts, obtained at low temperatures, the 
other of products, resulting from destructive distillation ?_t 
high temperatures. A few are by-products of chemical reac- 
tions, which are referred to the third group. 

Concerning this subject, three notable papers have lately 
been published that deserve the serious attention of chemists 
and technologists throughout the civilized world. I refer to: 

First, 'The International Association for Testing Mate- 
rials, Brussels Congress 1906, Report on Problem 34; Fixing 
a Uniform Definition and Nomenclature of Bitumen, Pre- 
sented by the Chairman of the Commission 34, Professor Dr. 
G. Lunge, with an Appendix; Investigations of Asphalt, by 
G. Lunge and V. Krepelka, translated by E. Ormond, Zurich." 
While this translation is very free, and sometimes incorrect, 
I have not observed many serious deviations from the mean- 
ing of either the French or German texts, with which I have 
made a careful comparison. 

Second, "Beitrag zum Nachweis von Verfalschungen im 
Naturasphalt, von Dr. H. Kohler, Perth Amboy, N. J." This 
paper was published originally in the "Chemiker Zeitung," 
1906, 30, No. 5. 

Third, "Beitrag zum Nachweis von Verfalschungen im 
Naturasphalt, von Dr. Kohler, Betreibs-direktor der Riitgers- 
wirke-Aktiengesellschaft, Berlin." This paper was also pub- 
lished originally in the "Chemiker Zeitung," 1906, 30, No. 54. 

A critical examination of each of these papers will be in- 
dulged and then such general discussion and conclusions will 
follow as the occasion appears to warrant. 

Professor Dr, George Lunge, who is chairman of Com- 
mission No. 34, is the well known author of several works re- 
lating to the alkali and sulphuric acid industry, and also 'of a 
general work on Technology, the portion of which relating to 
bitumen was written by Prof. Dr. D. Holde, of the University 
of Berlin. 

Dr. Lunge was appointed chairman of a very able com- 



64 SOLID BITL'MEXS. 

mission, consisting of Vice-Chairman Dr. Jeno Kova.cs, Tar- 
tros, Hungary (deceased) ; and members : 

Dr. M. Albrecht, Hamburg; Dr. L. Eger, Munich; Prof. 
Dr. D. Holde, Berlin, Vorsteher der Abtheilung fur Ole am 
Konigl. Material-Prufungsamt. Gr.-Lichterfelde ; Prof. Em. 
Paterno di Sessa, Rome, Senateur du Royaume d'ltalie, pro- 
fesseur des applications de la Chimie a 1'Universite de Rome ; 
L. Schmelck, Stadtchemiker, Christiania; Dr. Max Bolim, 
Fabriksbesitzer, Privoz, b. m.-Ostrau ; Prof. B. Kirsch, k. k. 
technolog, Gewerbemuseum, Vienna ; Albert Grittner, Chef- 
Chemiker der kgl. ungar. Staats-bahnen, Budapest; A. W. 
Dow, Inspector of Asphalts and Cements for the District of 
Columbia, Washington, D. C. ; Clifford Richardson, Asphalt 
Expert, New York Testing Laboratory, Long Island City, 
N. Y. 

Quoting from the English translation of the report of Dr. 
Lunge above mentioned, "a circular in German, French and 
English was immediately addressed to the various members, 
in which the undersigned expounded his working program, 
and invited his colleagues to make him definite proposals 
founded on their own investigations, for a definition and 
nomenclature of bitumen." He further requested "to be in- 
formed of the different methods employed by them in analyz- 
ing and testing the different kinds of bitumen, to enable him 
to draw up a system of classification founded on these in- 
vestigations. In order that it would be possible for him to 
carry out the control analysis in his laboratory during the 
summer term, he requested that the proposals be sent to him 
not later than May I, 1903. 

"In October, 1902, he together with one of his students, 
Herr V. Krepelka, began an experimental work on the meth- 
ods of analyzing bitumen. This investigation was finished in 
the course of 1903. 

"Unfortunately only a very few answers were received 
by May I, 1903; the undersigned therefore issued a second 
circular in three languages, requesting replies on or before 
November I, and finally a third on November 20. * * * 

"The undersigned did everything in his power to push 
forward the work entrusted to him, but the result attained 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 65 

was very small, notwithstanding an extensive correspondence 
in three languages in addition to the circulars. 

"Very few answers were received although a second and 
third request were sent out. Dr. Albrecht, Dr. Eger, Engineer 
Locherer and Mr. A. W. Dow did not reply at all. Letters 
from Dr. Holde, L. Schmelck, A. Grittner, Profs. Kirsch and 
Paterno did not contain any important information. Mr. 
Richardson wrote fully and gave detailed information regard- 
ing American asphalt and the methods used by him in analyz- 
ing the same. He prepared between three and four hundred 
pages of manuscript, 'but feeling that his results were not 
such as could be placed before our commission, he declined to 
make any report.' ' 

Only two opinions on this subject of any importance to 
the commission were received, one from Dr. Jeno Kova.cs, and 
the other from Dr. Max Bohm. 

Dr. Kovacs (who was the Vice-Chairman of the Com- 
mission, now deceased, and who was an asphalt expert of the 
highest rank and a voluminous author on the technology of 
bitumens), states "that he understands under 'asphalt' only 
those materials consisting of or containing asphalt bitumen, 
the bitumen of which has resulted from natural resinification 
or oxidation. The materials which he divides into the fol- 
lowing classes, asphalt-bitumen, asphaltic stone, asphaltic 
sand, asphaltic mastic, liquid asphalt, compressed asphalt, in- 
sulating asphalt and asphaltic roofing paste, ought to be char- 
acterized by the following properties : they are elastic, do not 
soften at 40-50 C. or split or crack at low temperatures 
( I5a 20). They contain bodies that volatilize with diffi- 
culty and do not oxidize at the ordinary temperature, and are 
therefore least exposed to decay through atmospheric influ- 
ences. Pure bitumen is of a bright black color with a reddish 
shimmer and forms either a viscous, sticky, or else a hard and 
brittle mass which is not fluid under 35 C. It dissolves com- 
pletely in carbon disulphide, oil of turpentine and chloroform, 
partly in petroleum spirit and benzol, and is almost insoluble 
in alcohol. By the name 'artificial asphalt/ or more correctly 
'asphalt-surrogate' he designates those materials and products 
the chief component of which is not asphalt-bitumen, but coal 
tar pitch, petroleum pitch (according to him wrongly called 



66 SOLID B IT CM EX S. 

petroleum-asphalt or bitumen) or other similar resinous prod- 
ucts, which cannot be discriminated outwardly from the nat- 
ural products, but whose inferiority or uselessness shows itself 
in a short time because the binding substance does not possess 
the necessary physical and chemical properties." 

Dr. Kovacs accordingly limits the term "asphalt" to the 
genuine natural-asphalt, and will not hear of it being applied 
to the products of coal-tar or petroleum. 

"Dr. Bohm also limits the term 'asphalt' exclusively to 
the natural product, but describes the residues remaining after 
the distillation of petroleum, lignite-tar, coal-tar, and fatty 
acids according to their degree of fluidity as 'pitch' or 'tar' 
with a prefix showing the origin of the product ; as for in- 
stance, coal-tar, lignite-tar, petroleum-pitch, wool-fat-pitch, 
using 'bitumen' as a general term. Dr. Bohm agrees so far 
with Dr. Kovacs that not only the artificial bitumen produced 
from coal-tar, but also that derived from petroleum, ought not 
to be described as 'asphalt.' He does not, however, say how 
petroleum-pitch may be distinguished physically or analytic- 
ally from natural asphalt. 

"Mr. Grittner informs me that he has not been able to 
make such a distinction, and I have also come to the same 
conclusion after the exhaustive series of experiments made 
with Mr. Krepelka which are described in the appendix. 

"The tenor of Mr. Clifford Richardson's report amounts 
to the same. His argument is, that the formation of genuine, 
natural asphalt has been very similar to that of petroleum and 
that various transition stages exist between them, which easily 
explains why bitumen produced artificially from petroleum 
cannot be distinguished by any particular characteristic from 
natural asphalt. 

"For the same reason and also on the basis of my own 
investigations I consider that the term 'asphalt' should also be 
applied to products made from petroleum, but that a distinc- 
tion should be made between 'natural-asphalt' and 'petroleum- 
asphalt' (Erdol asphalt). On the other hand, I quite agree 
that the products made from coal-tar (and lignite-tar) and 
pitch can be distinguished from the asphalts, not only in prac- 
tical use, when they exhibit their inferiority, but also by lab- 
oratory tests, and should be classed as pitch and tar and not 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 67 

as asphalt. I cannot, however, extend this prohibition to the 
products made from petroleum ; firstly, because these products 
are genetically similar; secondly, because they cannot be dis- 
tinguished from one another with any degree of certainty in 
the laboratory; and thirdly, because I have no positive proofs 
that petroleum-asphalt, in reference to its technical uses, can- 
not hold its own in competing with the numerous kinds of 
natural-asphalt. Above all, I should certainly say that the 
term 'natural asphalt' ought never to be used for the products 
artificially prepared from petroleum." 

In the appendix is described in great detail, the researches 
that were conducted during six or eight months. Nine natural 
asphalts, four petroleum pitches and two coal-tar pitches were 
extracted with chloroform and the extract evaporated under a 
temperature of 150 C. 

"The pure bitumen was then investigated regarding its 
specific gravity, melting point, the specific gravity of the chlor- 
oform solution, and its iodine value. Dr. Lunge then says, 'No 
experiments were made in the direction of fractional solution, 
fractional distillation, analysis by combustion, etc., etc., partly 
because only in a few cases had we sufficient material, and 
partly because the investigation of such a number of sub- 
stances would have taken too long. As we learned from ex- 
perience, a really useful classification of the various materials 
in this manner would have offered too many difficulties for 
technical as well as scientific purposes.' " 

In his "Conclusions" he makes the following remarkable 
statements : "On the addition of petroleum benzine to a 
chloroform solution of coal-tar-pitch a precipitate is formed, 
which is not the case with natural or petroleum asphalts." It 
was not, however, found "possible to distinguish quantita- 
tively between natural asphalt and 'petroleum asphalts' ob- 
tained from petroleum. This can scarcely be wondered at as 
it is a generally accepted view that the 'asphalts' (semi-solid 
or solid 'natural asphalt'), found in nature mixed with more 
or less mineral and other impurities, stand in very close re- 
lationship to the more or less liquid petroleums and are formed 
from these by analogous processes to those by which 'petro- 
leum-asphalt is prepared artificially from oils.' ' ! 

The first paper by Dr. Kohler mentioned above starts out 



68 SOLID DITUMEXS. 

by quoting the statement of Lieut. Malenkovic "that the rang- 
ing of petroleum pitches in line with natural asphalts can be 
proved scientifically only under constraint." His argument is, 
that in the formation of natural asphalts rapid processes have 
certainly not taken place, as is the case in the originating of 
the petroleum pitches under the influence of concentrated and 
fuming sulphuric acid. Against this must the objection be 
raised that at least here in America, and probably in other coun- 
tries as well, large quantities of petroleum asphalt are traded 
in, from the process of formation of which the influence of 
sulphuric acid is excluded; they are simply residues of raw 
oil distillation, which frequently have been condensed (or 
polymerized) by blowing in of air or treatment with sulphuric 
acid. * * * In science the opinion prevails generally now- 
adays, that the natural asphalts are not only intimately an- 
alogous to the mineral oil, but that they should be considered 
straightway as having originated from them, whether a slow 
evaporation of the more volatile, with gradual oxygenation of 
the more complex ingredients is at the bottom of it as the 
older school holds, or that, which is more probable, a con- 
densation and polymerization (Mabery and others), or finally, 
that besides these, simultaneously, a removal of hydrogen has 
taken place. (G. Kraemer). * * * This investigation has 
demonstrated that the action of sulphuric acid on raw mineral 
oil is even essentially polymerizing; resinous bodies possess- 
ing acid properties separating from the acid used in purifica- 
tion, after its dilution with water consist of polymerized pe- 
troleum components of a boiling point of more than 300 and 
are in no wise different from natural asphalt or bitumen. It 
makes no difference for the chemical nature 'of the asphalt, 
whether such process has been consummated slowly in the 
course of time or whether rapidly under the influence of chem- 
ical reagents, as this is a fact that holds good for other prod- 
ucts of polymerization." 

He then proceeds to compare ultimate analyses of natural- 
bitumens and petroleum residuums and begs the whole ques- 
tion by asserting that the substances analyzed have not been 
proved to be different and are therefore identical. 

He further strengthens his position by quoting the report 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 69 

on the experimental work of Lunge and Krepelka which has 
been quoted at length in this paper. 

I next take up the third paper under discussion that is 
mentioned above. After some personal explanation, Dr. 
Kohler says he selected certain analyses of asphalt for com- 
parison, with the remark : "I have confined myself to stating 
the contents of hydrogen and carbon, not even mentioning the 
sulphur, which was advisable for the very reason that the 
analyses of the simultaneously adduced artificial asphalts 
(pitches) do not take the latter into consideration at all." He 
seems to be without knowledge of the fact that a large part, 
if not all of the sulphur has been burned out of the residuums 
in the process of distillation, and further contends in support 
of this remarkable statement, that "concerning the by far 
major part of the sulphur, however, it is not yet even settled 
whether it can be considered as chemically bound, because 
such proof, owing to the well known peculiarity of the sulphur 
to dissolve in high molecular carburetted hydrogen compounds 
is by no means an easy task." 

Again he says: "It requires no argumentation to show 
that petroleum pitches, being the residues of distillation carried 
to considerably high temperatures, cannot contain any more 
fractions of low boiling point; why the mineral-pitches 
(Erdpeche) should furnish them is easily comprehensible, for 
they contain, just because they are not residues of distillation, 
a part of those highly volatile hydrocarbons of mineral oil out 
of which they originated by a process of polymerization or 
oxidation, which have remained excluded for some reason or 
other from transformation into asphalt. That those highly 
volatile fractions of the mineral-pitch are not to be consid- 
ered as pyrogene products of decomposition of the former, is 
evident from the fact that it is possible to isolate them by 
extraction with suitable solvents, as well as by fractional dis- 
tillation. Therefore no decisive significance can be attached 
to the distillation curve relative to the question as to the 
identity or difference of the natural asphalts and the petro- 
leum pitches." 

He then goes on to say: "In Mr. Richardson's opinion 
(See The Mod, Asph. Pavement, p. 145) the asphalts consist 
of a mixture of saturated and unsaturated polycyclic hydro- 



70 SOLID BJTi'Ml-\S. 

carbons as well as derivatives thereof of sulphur and nitrogen. 
* * * True asphalts contain nearly no bitumen which is 
insoluble in cold carbon-tetra-chloride, but soluble in carbon- 
di-sulphide; the bitumen of the asphalts soluble in the last 
named solvents is called 'asphaltene' and cannot be melted 
without decomposition. 

"The petrolenes or malthenes consist, according to the 
hardness of the bitumen, of 20 to 50 per cent of saturated di- 
or polycyclic hydrocarbons (polymethylenes) of the series of 
Cn H 2 n- 2 and Cn H.,n- 4 , the lowest member of which, C 13 H 24 , 
with a boiling point of 165 C, has been found in Trinidad 
asphalt; they consist further of unsaturated hydrocarbons, 
which are easily soluble in concentrated sulphuric acid, the 
nature of which is not sufficiently understood ; also of sulphur 
compounds which can be isolated in the same manner and 
have been found identical with those of the mineral oils of 
Ohio, Canada and California, and of nitrogen compounds 
which probably have the same relation to the polymethelenes 
as chinolin has to benzol. 

"The asphaltenes are probably unsaturated hydrocarbons, 
or derivatives of them, in highly condensed form, possessing 
a very high molecular weight, but concerning their structure 
we know comparatively nothing. They contain the major 
part of the sulphur extant in asphalt (in what form is not said, 
K) and are characterized usually by the presence of remark- 
able quantities of it. The larger the content of sulphur the 
harder the asphalt. 

"Normal asphalts leave, after heating, about 15 per cent 
coke residue, a fact which enables us to distinguish them by 
this characteristic alone from other solid bitumens." 

I have made the foregoing extracts from these papers in 
order to present the views of their authors with sufficient 
clearness and thereby to set forth the grounds for the criti- 
cism that follows. 

The President of the International Association for Test- 
ing Materials saw fit to appoint a committee consisting of a 
number of the most prominent investigators of bitumen then 
living. He placed at the head of the committee a very emi- 
nent man who had devoted many years to a totally different 
field of research. His report proves the absolute unfitness of 



CLASS 11' 1C ATI ON OF BITUMINOUS SUBSTANCES. 71 

the selection. Had he possessed even an elementary knowl- 
edge of the subject submitted to the committee he would 
have pursued an entirely different course. He details, in his 
report, the apparent indifference of his associates, and then 
proceeds to demonstrate that the indifference was all his own, 
for the advice of the few eminent men who sought to coop- 
erate with him was wholly ignored, and only inadequate and 
negative results of ill-timed and hasty investigations, in 
which his eminent colleagues took no part, were presented in 
this report, with an excuse that really effective research work 
was not entered upon for lack of time. Every member of the 
committee knew, as soon as he received the ambitious pro- 
gram circulated in three languages, that the chairman of the 
committee had no adequate conception of the magnitude of 
the task he had undertaken ; hence, the seeming indifference 
to the importance of a subject in which every member of the 
committee would have manifested the liveliest interest had the 
matter been properly submitted for their active cooperation. 

While this criticism may seem harsh, let us see if the 
report made by Dr .Lunge does not fully justify it. He says 
only two reports of any importance were received by him 
from any member of this committee; one from Dr. Kovacs, 
the other from Dr. Bohm. They both emphatically declare 
that the term "asphalt" should not be used to designate arti- 
ficial products, that is, residuums and pitches. Yet, ignoring 
the conclusions of these very eminent specialists in bitumen, 
he proceeds on purely negative evidence to assume that the 
term "asphalt" should be applied to substances made from 
petroleum, but not to those made from coal-tar and similar 
products. 

His experiments were, first, the determination of the spe- 
cific gravities of the extracted bitumens. Extracted bitumens 
are not technological products. An extracted bitumen may 
have a specific gravity identical with a petroleum residuum 
to the third place of decimals and yet contain elements, or- 
ganic compounds, and even mineral ingredients, not found 
in the petroleum pitch. The extracted bitumens and re- 
siduums have a specific gravity of about i.o; some sink in 
water and some float. If equal parts are dissolved in equal 
parts of chloroform or any other neutral liquid, no appreciable 



72 SOLID BIT CM EX'S. 

difference in the specific gravity of the solutions could reason- 
ably be expected. 

Nor is the melting point of anyching more than sugges- 
tive or of arbitrary value. 

Perhaps more might be expected of the iodine values, but, 
when a proper consideration is had of the fact that solid bitu- 
mens are mixtures like liquid bitumens of proximate princi- 
ples at present unknown in composition and proportional 
amount, such a purely empirical reaction as the iodine reac- 
tion signifies very little. 

If any member of Dr. Lunge's committee had spent a 
summer's vacation with a graduate student investigating any 
of the vital problems involved in the manufacture of acids and 
alkalis, no one would more readily and accurately judge the 
inadequacy of any negative opinions they might express, than 
Dr. Lunge. 

The work he left undone for lack of time, every asphalt 
chemist knows is the work that will fill the 2oth century with 
honorable research by those who are so fortunately situated 
as to be able to conduct it. I can well remember the smile of 
incredulity with which Cyrus M. Warren listened to me, 
when in 1865 I opened several cans of California petroleum 
in his laboratory in Boston, and assured him that I had in 
them a new kind of petroleum that contained nitrogen and 
benzoles instead of paraffines. I well remember, too, the re- 
luctance with which technologists admitted that California 
petroleum does not contain the hydrocarbons that are found 
in illuminating oil of good quality, yet this fact was demon- 
strated at an enormous cost, long before Mabery had proved 
by an elaborate research that those oils contain 20 per cent of 
nitrogenous basic oils, and little or no paraffines. Experi- 
ments without number, similar in many respects to those 
made by Dr. Lunge, in which I myself took part, had pro- 
duced illuminating oils unsurpassed in color and appearance, 
some of which were pronounced by experts equal to any ever 
made, but they always proved inferior when burned under 
equal conditions with oils made from Pennsylvania petro- 
leums. 

Opinions, probabilities and negative results will never 
prove that unlike things are alike. Those who wish them 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 



73 



alike for commercial reasons can devote pages to fruitless 
argument and thousands of dollars of public funds to the at- 
tempt to make unlike things alike, but the truth always pre- 
vails in the end. 

Dr. Kohler assumes that all natural asphalts are derived 
from petroleum. This assumption is not based on the ob- 
served facts of nature, technology or chemistry. He further 
assumes that the conversion of petroleum into asphaltum by 
natural causes is due to polymerization. When in California 
I proved by experiment that petroleums, placed in an open 
vessel on a window seat, exposed to direct sunlight, evapo- 
rated, both by weight and measure, with great rapidity, losing 
a portion of their contents that distilled at a temperature 
above the boiling point of water. I proved also by experi- 
ment in 1870, that California and Pennsylvania petroleums, 
subjected to parallel treatment, where air, ozone, chlorine, or 
other gas that would combine with hydrogen is aspirated 
through them, is in the first case converted into asphaltum- 
like compounds with loss of hydrogen, and in the second case 
is evaporated to a vaseline-like residue. While giving many 
negative results and possessing many physical properties in 
common, these petroleums are totally unlike. Any one can 
prove theoretically that parafiine molecules cannot be con- 
densed by polymerization. If the molecule is doubled it is 
no longer a paramne. Neither can complex molecules con- 
taining nitrogen and sulphur substitution compounds be poly- 
merized, nor are they. The bitumens of Trinidad pitch give 
up sulphur as hydrogen sulphide below the boiling point of 
water, as I have proved by experiment. The California petro- 
leums when put into a still yield large quantities of hydrogen 
sulphide at comparatively low temperatures. They cannot be 
distilled either with or without steam without decomposition. 
I have also proved by repeated experiments that both chloro- 
form and turpentine solutions of Trinidad pitch and other 
natural solid bitumens are precipitated on addition of an ex- 
cess of petroleum ether and these precipitates often contain 
sulphur. There is practically no sulphur in petroleum resid- 
uums. The original Dubb's process consists in treating the 
oil with sulphur, which escapes as hydrogen sulphide, burn- 
ing out the hydrogen. Air passed through the hot oil burns 



74 SOLID BITL'MEXS. 

out the hydrogen in clouds of steam. When the crude dis- 
tillates from these oils are treated with concentrated sulphuric 
acid the tanks are enveloped in stifling clouds of sulphurous 
oxide. There is every indication of very active decomposition 
of both oil and acid. To call all these phenomena polymeriza- 
tion and to liken them to the operations of nature is constraint 
that amounts to audacity. Where in nature are such reac- 
tions observed? As I have said elsewhere, we cannot reason 
from the processes of technology, bounded as they are by 
time and space, to the infinity of nature in which time enters 
without limit in sufficient quantity. 

The statement of Malenkovic that Dr. Kohler quotes with 
emphatic disapproval, "that the proof for the chemical identity 
of petroleum pitches with natural asphalts has hitherto not 
been adduced any more than the proof that they are service- 
able as natural asphalts," expresses an absolute truth, and is 
only met by Dr. Kohler with assumptions and probabilities. 
In his second paper on page 2 (of the paper) he gives two 
tables in which I am quoted as having published ultimate 
analyses of Trinidad pitch in which the sum of the percent- 
ages of carbon and hydrogen equal 100. I never made an ulti- 
mate determination of carbon and hydrogen in any solid bitu- 
men in my life. I never had any time to waste in any such 
fruitless work. To quote such results along with those of 
Boussingault made more than 60 years ago, before the pres- 
ence of sulphur in bitumen was suspected and when oxygen 
was determined by difference, is worse than a waste of time 
it is folly. 

After some rummaging, I found the source of this blunder 
in a paper that I published in the Journal of the Society for 
Chemical Industry for November, 1898. The sentence reads 
as follows : "Mr. Richardson gives a table by which he at- 
tempts to show that the bitumen of land pitch contains more 
carbon than the bitumen of lake pitch. His figures do not 
warrant his conclusion. His average of land pitch contains 
83.68, H 10.84, total 94.52 of hydrocarbon; of which 88.426 
per cent is carbon and 11.574 per cent is hydrogen. His lake 
pitch contains 82.33, H 10.69, total 93.02, of which 88.507 per 
cent is carbon and 11.493 P er cent * s hydrogen." If this 
blunder measures Dr. Kohler's familiarity with the literature 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 75 

of bitumens, the vagaries of his conclusions need not occasion 
remark. 

So Dr. Lunge refrains for lack of time in engaging in a 
research that Dr. Kohler regards as a by no means easy task, 
and both substitute for the laborious proof of the laboratory, 
those "scientific uses of the imagination" that appear as as- 
sumptions, opinions and probabilities upon which, as a foun- 
dation, any superstructure can be erected that suits the fancy. 
It is so easy to assume that natural fluid bitumens are not 
distillates because they contain very volatile constituents. 
Did Dr. Kohler ever study the coal-oil or Scotch shale indus- 
tries? If he has, he has found the crude distillates of those 
shales and coals to very closely resemble natural petroleums 
of the" Pennsylvania variety. They are both liquids that 
largely consist of paraffines, and neither of them, by nature 
or art, can be converted into asphaltum. It is only necessary 
to subject the coals and shales to distillation at the lowest 
possible temperature to obtain the whole range of paraffines 
found in Pennsylvania petroleum. If these crude distillates 
are again distilled, light and heavy fluids will be obtained, and 
residual pitches, that are black and lustrous with a conchoidal 
fracture and without either odor or taste ; yet, they are neither 
anthracite coal on the one hand nor glance pitch on the other; 
they are simply, to use Mr. Richardson's felicitous phrase, 
"residual pitches." 

This is the latest discussion on this subject. It is greatly 
to be regretted that Dr. Lunge's committee accomplished so 
little. 

This discussion, however, deals with names as well as 
things. I am convinced that by a happy inspiration, Malo, 
in the first instance, formulated a title to his table of 1863 
that cannot be improved, viz. : "Tableau synoptique des ma- 
tieres bitumineuses.''* Under this comprehensive title he 
arranged those substances that the scientific and technical 
knowledge of that period brought under it; but, the more 
than forty years that have since passed have greatly added 
both to our knowledge of the substances included by him in 
his table, and also to the number of substances properly in- 

*Sur L'Asphalte, M. Leon Malo, Paris, 1863. 



76 SOLID BITUMENS. 

eluded in such a table. This being the case, while the title 
may properly be retained as he used it, a rearrangement of 
the contents of the table becomes desirable. 

Bituminous materials naturally fall into three great 
classes, viz. : Class A, pure bitumens, as they occur in na- 
ture ; Class B, pyro-bitumens, or substance yielding by heat, 
educts and products more or less closely approximating nat- 
ural bitumens ; Class C, the artificial substances, resembling 
natural bitumens, obtained as educts or products from pyro- 
bitumens and other crude materials, usually by distillation, 
but often by chemical processes, which may properly be 
termed "factice" or ''factitious bitumens." 

Class A includes all of the natural bitumens, from natural 
combustible gas to the most pure and solid glance pritch, to- 
gether with all the mixtures of bitumens with various kinds 
of minerals as they occur in nature. 

These materials are : 

(1) Natural combustible gas as it occurs in gas wells; 
also as it escapes from petroleum wells, and also as it escapes 
from springs of water, producing the phenomena of burning 
springs. 

(2) Natural naphtha, usually nearly or quite color- 
less, and very volatile and ethereal, occurring in Persia and 
different parts of the world accompanying the water of 
springs, and in a few instances, flowing from wells with the 
escaping gas. 

(3) Rock oil or petroleum, an oily fluid, varying in 
color from a pale amber through red and green to black. It 
occurs flowing from natural springs and accompanying water, 
also flowing from artesian wells and pumped from them. It 
is very widely distributed and at present forms the principal 
illuminating and lubricating material of commerce. The vary- 
ing chemical composition of petroleum gives rise to a great 
variety of oils from different localities. 

(4) Maltha or mineral tar. This material is a brown or 
black, intensely viscous, fluid. It has usually resulted from 
the evaporation and decomposition of petroleum. Only cer- 
tain varieties of petroleum are susceptible to the necessary 
change?. Maltha generally contains gas and water entangled 
in its viscous mass, which causes the liquid when heated to 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 



77 



froth violently. Some of the water appears to be chemically 
combined with the maltha as water of hydration of basic oils 
that form a part of it. 

(5) Fossil paraffine from Galicia, Utah and elsewhere. 

(6) So-called asphaltic coals, Grahamite, Albertite, Gil- 
sonite, etc., which yield paraffine on distillation. 

(7) Asphaltum from the Dead Sea, Mexico, the West 
India Islands ; glance pitch, yielding on distillation other 
hydrocarbons than paraffine. 

(8) Maltha mixed with limestone or chalk, Seyssel, etc. 

(9) Maltha mixed with sandstone, from many European 
and American localities. 

(10) Maltha mixed with sand, Oklahoma, etc. 

(n) Maltha mixed with earthy matter, Trinidad Lake, 
etc. 

All of these pure bitumens may be refined at low temper- 
atures or distructively distilled at high temperatures. 

Class B includes all of the coals from peat to anthracite 
and all of the bituminous schists and shales. Anthracite is 
not strictly a pyro-bitumen, but it is introduced here to show 
its relations to other coals. This class 'of substances was very 
properly called by Dr. T. Sterry Hunt, "pyro-bitumens." 

This class embraces : 

(12) Peat, from localities all over the world. 

(13) Lignite or brown coal, all over t&e world. 

(14) Bituminous coal, all over the world. 

(15) Semi-bituminous coal, all over the world. 

(16) Anthracite coal, all over the world. 

(17) Boghead mineral and other Scotch shales, with the 
paraffine shales of New South Wales, etc. 

(18) Bituminous schists of Autun and other localities. 
All of these pyroschists may be made to yield upon distilla- 
tion, gaseous, liquid or solid, educts or products, resembling 
natural bitumens. The character of the distillate will depend 
upon the temperature. At low temperatures, the distillates 
will be dense and they will decrease in density as the temper- 
ature is raised until at very high temperatures the dissocia- 
tion will be complete and the distillate will consist of hy- 
drogen gas, with a residue of fixed carbon, "the carbon of the 
gas retorts," or coke. 



7 8 SOLID BITUMENS. 

Class C includes the educts obtained by distillation of 
pure bitumens and pyrobitumens at low temperatures; the 
products obtained from the same at high temperatures ; and 
certain by-products of chemical processes. All of these prod- 
ucts and by-products result from decomposition of either 
recent or fossil organic compounds by the application of heat 
or chemical reactions. It is often observed that liquid bitu- 
mens, such as the different varieties of petroleum, may be 
distilled into educts until a temperature is reached at which 
decomposition of the contents of the still follows, if the dis- 
tillation proceeds. As an illustration : The so-called asphalt 
oils of southern California, when put into a still, yield at first, 
very volatile fluids that are colorless and ethereal. As the 
temperature rises, decomposition (dissociation) commences, 
hydrogen sulphide, and other gases, escape and may be 
trapped off from the condenser and used to heat the still. 
The liquid distillate increases in density, the odor becomes 
very rank, and the residue remaining in the still, when run 
out and cooled, is a solid mass, varying in composition and 
properties according to the proportion of distillate that has 
been run off, from a very brittle to a very cohesive and plastic 
solid, which is, as far as I could discover after a prolonged 
and very careful examination, asphalt only in name.. These 
residuums are properly called "factice." 

This class embraces: 

(19) Coal gas, street gas, illuminating gas. 

(20) Refined petroleum, illuminating oil, coal oil, kero- 
sene. 

(21) Reduced oil, lubricating oil. 

(22) Paraffine, cosmoline, ceresine. 

(23) Coal tar, blast furnace tar, coke oven tar, yielding 
on distillation benzoles, dead oil, anthracene and pitch. 

(24) Residuum of petroleum, residuum oil. 

(25) Pittsburg flux, "Dubb's asphalt" bylerite. 

(26) Solid residuum of California and Texas petroleum. 

(27) Coke pitch and brittle residuums of petroleum, 
coal-tar pitch. 

(28) Coke from gas works and coke ovens. 

(29) Sludge acid tar and pitch. 

(30) Candle tar. 



CLASSIFICATION O7< BITUMINOUS SUBSTAXCES. jq 

In these thirty items are included the bituminous mate- 
rials known at the present time, many of which were un- 
known or but little known in 1863, when Malo first attempted 
to classify bituminous materials. I have made no attempt 
to give them specific names. I have simply enumerated in 
their proper order the substances to be named. I have too 
little familiarity with the French and German languages to 
even suggest names of these very varied substances, that may 
be uniform in the three languages. This was the problem sub- 
mitted to Dr. Lunge's committee that was left unsolved. I 
suggest that no name or system of names should be applied 
alike to the natural and artificial substances found in classes 
A and C, with any expectation that present and prospective 
confusion will be avoided. To give a common name asphalt 
to the asphaltum of the Dead Sea, to Gilsonite, to Seyssel 
rock and the residuum of California petroleum, with other un- 
like things too numerous to mention, betrays a deplorable 
poverty of language ; no more consistent with scientific ac- 
curacy than would be the calling of orthoclase, albite, labra- 
dorite, pumice, 'obsidian, glass and enamel by the name of 
feldspar. 

From all that precedes the following conclusions are 
legitimate. 

(1) That the proof is beyond question, that for years the 
interested vendors of bituminous products, ^especially those 
used in street paving, have been quibbling with the use of 
words until no confidence can be placed in their definitions. 

(2) That numerous authorities have brought together 
convincing proof of the proper definition of the following 
English words :* 

Asphalt, synonymous with Asphaltum ; the solid form of 
natural bitumen. 

Asphalte, a limestone saturated with bitumen, occurring 
at Seyssel and elsewhere. I have suggested the use of 
this word to designate not only limestone, but sandstone and 
sand saturated with bitumen, thus : 

Asphalte, calcareous, Seyssel, Oklahoma, etc. 

Asphalte, silicious, Lobsann, Oklahoma, etc. 

'Report on Asphalt, Commissioners of Accounts of the City of New 
York, Feb. 3, 1904. 



go SOLID B IT I'M EX S. 

Asphalte, earthy, Trinidad. 

Asphaltite, minerals occurring in true veins, having some 
of the properties of asphaltum and also of bituminous coal, 
yielding paraffin e on distillation, Albertite, Grahamite, Uin- 
taite, or Gilsonite. 

Bitumen, a generic term including substances occurring 
in nature, in outflows or springs, and in veins, as natural in- 
flammable gas, fluid petroleum, viscous maltha and solid as- 
phaltum and asphaltite. It also occurs saturating and mixed 
with limestones, sandstones, sand or earthy matter. These 
mixtures are called asphalte. Bitumen varies greatly in phys- 
ical properties and composition. It consists mainly of carbon 
and hydrogen with oxygen, sulphur and nitrogen in very com- 
plex compounds, regarding which chemists have much to 
learn. 

Maltha, a viscous form of bitumen in many cases shading 
from petroleum on the one hand to asphaltum on the other. 

Naphtha, a volatile ethereal form of bitumen, rarely met 
with in nature. A name frequently applied to the most vola- 
tile distillate of petroleum. 

Natural Gas, combustible gas, escaping from fissures in 
the earth and springs (burning springs) and drilled wells. It 
often accompanies petroleum and escapes from petroleum 
wells. 

Petroleum, Rock Oil, issuing from springs and wells. It 
is usually accompanied with water and "natural gas." Some 
kinds consist of a complex mixture of nearly pure compounds 
of carbon and hydrogen ; others contain compounds of oxygen, 
sulphur and nitrogen. 

(3) That the use of the word asphalt to designate bitu- 
minous rock leads to confusion and should be discouraged. 
That the use of the French word spelled with a final e to des- 
ignate natural asphaltic mixtures whether calcareous, sili- 
ceous or earthy would lead at once to clearness of definition 
among English speaking people, but, perhaps is not equally 
clear in German and French. 

(4) That the use of the words asphalt and bitumen to 
designate substances that are not found in nature is wholly 
unwarranted and cannot be justified by any plea of custom 



CLASSIFICATION OF BITUMINOUS SUBSTANCES. 81 

when such custom leads to confusion in the definition and 
construction of specifications and other legal documents. 

(5) That the adoption of specifications in which the 
word "asphalt" is defined in such a vague and unwarranted 
manner as practically to define nothing, admits of the use of 
a great variety of materials that are not natural products at 
all, nor are they asphalt at all, as defined by the highest 
authorities. 



CHAPTER IV. 

DERIVATION OF NATURAL SOLID BITUMENS. 
(i) EVAPORATION. 

While the most extensive deposits of solid asphaltum are 
found in injected veins that fill fissures in the earth's crust, 
the doctrine is advocated by numerous authors that petro- 
leum is the primary source of all these solid bitumens and that 
these veins were originally filled with a liquid that has been 
inspissated. Inspissation when used in this connection can 
mean nothing else but evaporation. How the walls of these 
enormous crevices were held asunder while the inspissation 
proceeded ; why the lower portions, often several hundred 
feet from the surface are not of a more liquid consistency 
than that at the surface; in what manner a residue of 10 per 
cent could fill the space occupied originally by the 100 per 
cent of liquid and what suspended the angular horses in a 
liquid at a point in the vein only a few feet below the cavities 
from which they fell, are questions that the advocates of this 
doctrine have never answered, although the questions were 
asked nearly forty years ago. The author has examined per- 
sonally some of these veins and has read descriptions of 
others, and concludes that these questions are properly asked 
concerning every one 'of them and should be answered. 

There are horizontal beds of asphaltum that occur in 
California, Mexico and Cuba and also in Albania and other 
localities in Europe-Asia, in the formation of which, evapora- 
tion of liquid bitumen as it oozed from orifices in rocks or 
was brought to the surface by the water of springs, has 
played an important part. 

(2) DECOMPOSITION. 

Whenever asphaltum has been formed from the evapora- 
tion of petroleum, the partial decomposition of the liquid 
bitumen has contributed to the successive changes that con- 
vert the petroleum into maltha, and continuing, finally result 

82 



DERIVATION OF NATURAL SOLID BITUMENS. 83 

in a solid bitumen, that, if unmixed with earthy matter or 
organic impurities, will, on being melted, produce glance 
pitch. 

The paraffine petroleums will not produce asphaltum. 
These petroleums undergo evaporation and become a residue 
resembling solid paraffine more or less impure. Other petro- 
leums, containing unsaturated hydrocarbons, less stable under 
atmospheric conditions than the paraffine, readily undergo 
both evaporation and decomposition. The California petrole- 
ums have both nitrogen and sulphur. Probably oxygen enters 
the compound, being substituted for both hydrogen and sul- 
phur. 

The conversion of fluid and semifluid bitumens into solid 
bitumens by burning out the hydrogen with sulphur, oxygen, 
ozone, chlorine, etc., has been repeatedly performed on both 
large and small scales in manufactories and laboratories. The 
results vary with the raw material selected. Paraffine pe- 
troleums, like those of Pennsylvania and Ohio, are mainly 
evaporated to a gummy mass resembling vaseline, being little 
acted on by oxidizing agents, while bitumens like those of 
California, consisting largely of unstable, unsaturated hydro- 
carbons, are readily acted on by them, and are converted into 
hydrogen sulphide, water or hydrogen chloride, which es- 
cape as a gas and a condensed body that is solid and resembles 
in many respects natural asphaltum. These factitious asphal- 
tums will be treated further on in this work at greater length. 

(3) POLYMERIZATION. 

By polymerization is meant the aggregation or condensa- 
tion of two or more molecules into a new molecule. As an 
illustration, two molecules of C 2 H 2 may be condensed into 
one molecule of C 4 H 4 , or three into C 6 H 6 . As Prof. Mabery 
has remarked, polymerization cannot take place among mole- 
cules of the paraffine series as a multiple of any compound 
having- the formula Cn H 2 n-|- 2 would no longer preserve the 
ratio of carbon to hydrogen observed among the paraffines ; 
but any compound of carbon and hydrogen having an equal 
number of atoms of carbon and hydrogen may be polymer- 
ized indefinitely. 



84 SOLID BITUMEXS. 

Without any doubt, all three of these processes, viz. : 
evaporation, decomposition and polymerization, contribute to 
those changes which in nature convert liquid and semiliquid 
bitumens into solid asphaltum. It must not be assumed, that all 
solid bitumens are the product of these changes, for, it is 
inconceivable that the great fissure veins of asphaltum occur- 
ring in crevices in many localities could have been formed 
from petroleum which had filled these open fissures, for the 
long periods of time required to produce these changes. 
These bitumens occurring in fissure veins are the product of 
a natural distillation at a minimum temperature and pressure, 
from natural causes, acting upon deep-seated strata. 



CHAPTER V. 
DERIVATION OF BITUMINOUS ROCKS. 

There are several different varieties of bituminous rocks, 
which have without doubt been produced by phenomena, 
identical with or similar to those which have produced solid 
bitumens. They have resulted from the condensation of 
semi-fluid bitumens in the form of vapor in rock masses that 
were originally more or less porous. 

It is not the condensation of petroleum, but maltha, that, 
penetrating these rock masses in the form of heavy vapors, 
has become condensed, thus forming a solid rock mass, some- 
times completely saturated, and at other times presenting all 
degrees of partial saturation. The greatest variety of bitu- 
minous rock masses occur in Oklahoma. There are 
crystalline limestones presenting every degree of partial 
saturation ; masses of magnesian chalk resembling the bitu- 
minous chalk of Neuf Chatel ; carboniferous limestones con- 
sisting largely 'of fossil shells, every interstice of which is 
filled with bitumen. There are also sandstones saturated with 
bitumen and masses of sand and conglomerate that fall as- 
sunder as soon as the bitumen is removed. These rock masses 
and beds of sand were formed before they w T ere penetrated 
by the bituminous vapors. 

That the sand was not cemented into sandstone before 
the bituminous vapor penetrated it, is abundantly proved by 
the fact that when these bituminous sands are placed in boil- 
ing water, the sand and bitumen separate, the clean sand 
sinking to the bottom of the vessel while the bitumen rises to 
the surface of the water nearly free from sand. The bitumen 
thus separated is semi-fluid maltha, not petroleum. 

A curious rock mass occurs in Oklahoma near 
Dougherty. It consists of fragments of limestone and chert 
cemented into a solid rock mass with bitumen. 

When the bitumen is dissolved out of the Turrelltite of 
Texas, the mineral residue retains its form and is found to 

85 



86 SOLID BITUMEXS. 

consist wholly of shells and fragments of shells cemented to- 
gether at their points of contact. That they had been sub- 
jected to the action of steam or hot water before they were 
penetrated by the vapors of bitumen is proved by the presence 
in the cavities of the larger shells of crystals of calcite in vari- 
ous forms along with fragments of shells. The carbonate of 
lime had been dissolved in the hot water, very likely under 
pressure, and redeposited in the cavities of the shells as 
calcite, before the bitumen \vas condensed in the interstitial 
spaces. 

When the bitumen is dissolved out of the Seyssel rock 
there remains a coherent mass of nearly white chalk. These 
natural rock masses must have been penetrated by vapors 
that were distilled at the lowest possible temperature, hence 
the vapors were never subjected to overheating as is often the 
case with butimens that are residues from destructive distilla- 
tion, such as the residues from the various methods used in 
distilling petroleum. This fact accounts for the superior qual- 
ities often exhibited by these natural rocks over the most 
skillfully prepared artificial mixtures. 



CHAPTER VI. 
DERIVATION OF ARTIFICIAL SOLID BITUMENS. 

Nearly forty years ago, the author discussed the chemical 
phenomena associated with the "distillation of bitumens" at 
high temperatures, technically termed "cracking." This term 
was at first used in the technology of liquid petroleums, and 
crude coal oil distillates, to designate the slow destructive dis- 
tillation of residues that were too dense for illuminating oil and 
too light for lubricating oil, that accumulated in refineries. 
The process became of great technical value. No research has 
been undertaken, to the author's knowledge, to prove in what 
manner the products of cracking are related to the crude 
petroleum that is subjected to the process. Dr. C. F. Mabery 
has shown, on purely theoretical grounds, that paraffines can- 
not be molecularly subject to polymerization. On theoretical 
grounds it is equally certain that the paraffine molecule can- 
not be wholly cracked into molecules that are paraffines. 
Whenever a paraffine molecule is cracked, a part, at least, of 
the resulting molecules must be an unsaturated hydrocarbon 
molecule. For, cracking always results in a partial or com- 
plete dissociation of the carbon and hydrogen atoms. If the 
process is carried on at a low temperature the result is a fluid 
distilling at a lower temperature than the crude material, the 
molecule of which contains more hydrogen atoms in propor- 
tion to the carbon atoms, and a fluid that accumulates in the 
still that distills at a higher temperature than the crude mate- 
rial, the molecules of which contain less hydrogen atoms in 
proportion to the carbon atoms. If the oil is allowed to 
trickle into a white hot gas retort, free hydrogen will escape 
from the retort and the pure carbon of the gas retort will re- 
main in it. If crude petroleum is cracked in a properly con- 
structed still, a large percentage of the petroleum may be 
run out of the still of such a consistency that when cold it 
will appear as a solid mass, resembling a pure asphaltum in 
appearance. It is not, however, identical with natural asphal- 

87 



88 SOLID B1TUMLXS. 

turn, because in the processes of nature time enters in suffi- 
cient quantity, which may become practically infinity, while in 
the processes of technology the conditions of the problem 
compel comparative haste. 

As a consequence, the products of the distillation of nat- 
ural fluid bitumens, under ordinary atmospheric conditions, 
are almost without exception products of destructive distilla- 
tion, or cracked products. Dr. Mabery has found that even 
the light, colorless paraffines cannot be distilled under atmos- 
pheric pressure without cracking. The colorless distillates 
from California petroleum cannot be distilled without crack- 
ing except under reduced pressure. In ordinary distillation 
on a large scale, California petroleums yield so much inflam- 
mable gas that it is trapped off from the condensers, and 
forms a large percentage of the fuel required to run the stills. 
The only source of this gas is the decomposition of the liquid 
bitumen, into a permanent gas that cannot be condensed, and 
residuum that becomes solid when cooled. Under these con- 
ditions, solid residues, resembling asphaltum are asphaltum or 
asphalt only in name, and therefore, in any nomenclature of 
bituminous- substances should be given a distinguishing name, 
in order that they may not be confounded with natural solid 
bitumens. 

There are also a number of other substances still further 
removed from identity with natural solid bitumens that are 
often, for various reasons, called asphalt or pitch. These are 
the solid residuums derived from the distillation of gas tar, 
coke oven tar, blast furnace tar, wood tar, etc. They are not 
identical with each other, and are in all respects very far re- 
moved from identity with natural solid bitumens. 

Still another class of substances is obtained by the distil- 
lation of tarry by-products of various processes of chemical 
manufacture. Sludge acid pitch, candle tar pitch and the tarry 
residue of the wood pulp mills, are mentioned in illustration 
of this class of substances. 

These highly artificial substances have been classed in 
our table of nomenclature as false or factitious bitumens, thus 
placing them in a certain relation to bitumen and at the same 
time separating them by a broad distinction from the natural 
bitumens that in some respects they simulate. 



DERIVATION OF ARTIFICIAL SOLID BITUMENS. 89 

Dr. Jeno Kovacs insists that "Holde's proposal to classify 
asphalts and allied products into four groups, i. e., tar, pitch, 
asphalt and coke, according to their hardness, is not consid- 
ered satisfactory to the asphalt expert as the origin 'of the 
material is not taken into account, whereas it is greatly to be 
desired that the name "asphalt" should in no case be applied 
to coal tar and naphtha products. Further, only three classes 
are held necessary, viz., tar, pitch and coke, as the pitch could 
be divided into hard and soft qualities if expedient." 

"For the classification of tar, pitch and asphalt materials 
it is recommended : 

"That the distillation products of coal tar and mineral 
oils be divided into three classes, viz., tar, pitch and coke. 
That the name 'asphalt 1 shall refer only to natural products, 
which occur only in the pure state or mixed with lime or sand, 
being, in the pure state, black and lustrous, and at the ordi- 
nary temperatures tough and sticky, or also solid and brittle, 
with a dropping point (see p. 274) not under 35 C. ; easily and 
completely soluble in carbon disulphide, turpentine and chlor- 
oform, with difficulty soluble in petroleum spirit and benzine 
and almost entirely insoluble in alcohol."* 



*Chem. Rev. Fett u. Harz-Ind., 1902, ix, p. 156-161; Jour. Soc. Chem. 
Ind., 1902, xxi, p. 1077. 



PART II. 

THE CHEMISTRY OF 
BITUMENS. 



CHAPTER VII. 

GENERAL CONSIDERATIONS CONCERNING THE 
CHEMISTRY OF SOLID BITUMENS. 

There are very few subjects of equal importance to chem- 
istry and technology about which chemists know so little as 
the chemistry of solid bitumens. Much that passes for scien- 
tific statement respecting the chemical composition of solid 
bitumens reveals the paucity of our knowledge and also the 
fact that beyond a few ultimate elementary analyses almost 
nothing is known concerning the complex constituents of 
solid bitumens. Mr. Clifford Richardson has done a large 
amount of work upon the proximate principles that are found 
in the distillates from Trinidad pitch, but his conclusions ap- 
pear to be assumed rather than proved. The author, by the 
use of solvents, has shown that Trinidad pitch is an exceed- 
ingly complex substance that cannot be distilled except de- 
structively. The same may be said of every other natural 
solid bitumen that has been subjected to research by any 
method hitherto employed. Notwithstanding these admitted 
differences a great mass of facts, the results of various re- 
searches, conducted by many chemists over a long period of 
years, have accumulated and are on record as constituting 
the chemistry of solid bitumens. 

The earliest research that was undertaken upon solid 
bitumens was that conducted by Boussingault in 1837, the di- 
rect results of which, though historically valuable, have been 
made in recent years to assume an importance out of all pro- 
portion to their intrinsic worth. In order that the readers may 
know for themselves exactly what Boussingault did, the 
author has translated and quoted his celebrated memoir en- 
tire, forming the subject matter of Chapter VIII. 



90 



CHAPTER VIII. 
MEMOIR UPON THE COMPOSITION OF BITUMENS.* 

Bitumens, so abundantly distributed upon the surface of 
the globe, and of which the uses appear to extend each day, 
have been little examined. It is to the deficiencies of chemis- 
try that the confusion is to be attributed into which mineralo- 
gists have fallen when they have essayed to classify bitumens. 
One can correctly define the composition, and assign a place 
in the system to naphtha, idrialine, or mellite, but when glu- 
tinous bitumens are reached, the difficulty begins; one sees a 
liquid, ordinarily liquid,, like petroleum, become viscous and 
present successively all degrees of consistency until asphalt, 
solid and brittle, is reached. It must be admitted, because 
of their great combustibility, that bitumens are essentially 
composed of carbon and hydrogen, and the water which some 
varieties yield on dry distillation, leads one to presume that 
they are not always free from oxygen. 

My attention has just been directed to the bitumen from 
the mines of Bechelbronn, in the department of the Bas-Rhin. 
In this locality they exploit beds of bituminous sandstone, 
which are a part of a very extensive Tertiary formation. Im- 
portant deposits of bitumen usually belong to recent epochs. 
They are also observed in basaltic tufas and trachytes, as at 
Pont-du-Chateau, in Auvergne. It is under equivalent geo- 
logical conditions that the immense masses of mineral tar are 
encountered at Mendez upon the banks of the Rio Grande at 
the Magdalena. 

When a bitumen is found in a fluid state, it suffices to 
separate it from the stones or impurities with which it is 
mixed. It is thus that the mineral tar can be obtained without 
much labor at Payta on the coast of Peru. But when the 
bitumen is intimately mixed with sand, as is the case in the 
Department of the Bas-Rhin, and at Seyssel on the banks 
of the Rhone, the extraction is made by boiling the mineral 

""Translated from the French of J. B. Boussingault. 

91 



92 SOLID BITUMEXS. 

with water. The bitumen floats on the surface of the boiling 
water, and is removed by the aid of skimmers. The first 
skimmings contain some sand, and are submitted to a new 
boiling. The second skimmings, after being placed in wooden 
tubs, and left to drain, are heated in a large boiler until the 
water is all evaporated. While cooling, the fine sand which 
still adheres to the skimmings, is deposited. The bitumen 
thus purified is given to commerce. 

Glutinous bitumens exhibit notable differences in their 
consistency according to locality. Those from Lobsann (Bas- 
Rhin) and from Seyssel (Am) are tenacious at the ordinary 
temperature. When cooled, they become solid. These bitu- 
mens are properly tars, but they are especially employed in 
the manufacture of bituminous mastic. The deposits at Pay- 
ta, those of the Magdalena, and of the Island of Trinidad, 
furnish bitumens that can be referred to the same variety. 

There are no important deposits of asphalt known in 
Europe. Asphalt which one sees in the collections comes 
from the Dead Sea, or Lake Asphaltites. The uses of this 
mineral are excessively limited. I can mention one very 
abundant mine of asphalt ; it is that of Coxitambo, near Cuen- 
ca, in Peru. Humboldt first described that locality, and ad- 
mits that the asphalt is found in place in the superior part of 
the red sandstone. 

I close this rapid review of the deposits of bitumen, by 
recalling that the outflows of naphtha and petroleum are met 
in abundance in the sandstone deposits of Asia, deposits that 
probably belong to a recent formation. The only fact which, 
in my opinion, indicates that bitumens are sometimes found 
in rocks of an ancient epoch, is that observed by Humboldt in 
Central America: This celebrated traveler saw petroleum 
springing from mica schist, beneath the sea at Punta de 
Araya, in the Gulf of Cariaco. 

The bitumen of Bechelbronn, which constitutes the prin- 
cipal subject of my work, is viscous, and of a deep brown 
color, its uses have given it the name of mineral grease, 
steinol, Strasbourg grease. This material is substituted with 
advantage for greases oi organic origin for lessening the fric- 
tion of machines ; and it is emplo3'ed with success for greasing 
the axles of vehicles. 



MEMOIR UPON COMPOSITION OF BITUMENS. 93 

Alcohol at 40 acts upon the bitumen, especially with the 
aid of heat; it takes a yellow tint; after having been treated 
with alcohol, the bitumen becomes much more consistent. 
Sulphuric ether very easily dissolves bitumen ; this solution 
permits the removal of the impurities that have escaped the 
refining. 

Submitted to a temperature of 100 in a flask the bitumen 
of Bechelbronn yields no product. It is thus evident that it 
contains no naphtha. This conclusion must be admitted a 
priori, from reflection upon the treatment to which the bitu- 
minous sand has been subjected. As a consequence, I have 
determined whether the sand contained naphtha before its 
treatment. A quintal of the sand immediately after its extrac- 
tion from the mines has been distilled with water and only 
a trace of naphtha has been obtained. 

In raising the temperature by means of an oil bath to 
230, drops of an 'oily liquid are seen to pass. At that tem- 
perature distillation takes place with extreme slowness ; but 
as one has in view the extraction of the volatile principles 
that bitumen could contain, without mixture of pyrogenous 
products, this degree of heat should .be maintained ; as, in 
order to obtain ten grammes of the oily matter distillation 
must be prolonged several days. 

This volatile oily matter constitutes the liquid principle of 
glutinous bitumen, and as it forms the essential part of petro- 
leum, I name it petrolene. In order to procure a sufficient 
quantity of petrolene, I have distilled with water the bitumen 
of Bechelbronn in an alembic which would hold two hecto- 
litres of water in which I placed 12 to 15 pounds of bitumen. 

The oil obtained by this means is very fluid, but it is sen- 
sibly colored brown. This was due to particles of the bitumen 
projected into the worm by the boiling water. The oil was 
rectified by distilling in a retort after drying over chloride of 
calcium. By this second distillation, the petrolene is obtained 
in a state of purity. 

Petrolene is of a pale yellow; its taste is a little marked; 
its odor recalls that of bitumen. At the temperature of 21 the 
density is 0.891. A cold of 12 causes it to lose its fluidity; it 
stains paper after the manner of the essential oils; when it 
burns it p'ours out a thick smoke. Petrolene thickens at 280 



94 SOLID BITUMEXS. 

of the thermometer ; alcohol dissolves a small quantity of it ; 
it is much more soluble in ether. 

The following analyses prove that petrolene is a hydro- 
carbon : 

Carbonic Acid. Water. 

I. 0.262 gave 0.837 0.303 

II. 0.282 gave 0.896 0.311 

III. 0.290 gave 0.927 0.310 

IV. 0.289 gave ..: 0.922 0.310 

I. II. III. IV. 

Carbon 0.833 0.880 0.885 0.384 

Hydrogen 0.121 0.122 0.119 0.119 



1.004 1.002 1.004 1.003 

Petrolene is isomeric with essential oil of citron, essence 
of turpentine, and oil of copaiba. As I have not combined 
petrolene with sulphuric and hydrochloric acids, I have taken, 
in order to learn its atomic weight, the density of its vapor 
by the process of Dumas. 

The vapor of petrolene weighs 9.415. 

20 volumes vapor of carbon equals 8.432 

16 volumes vapor of hydrogen equals 1.101 



9.533 
Multiplying by 4, for the atomic weight : 

80 atoms carbon, equal 3,060.8 

64 atoms hydrogen equal 400.0 

3,460.8 

After Dumas, the vapor density of essence of turpentine 
is 4.765. It is precisely half the vapor density of petrolene. 
Petrolene, like the oils that are isomeric with it, contains :* 

Carbon 0.885 

Hydrogen 0.115 

After treatment with alcohol, the bitumen of Bechel- 
bronn becomes stable; the alcohol becomes charged with pe- 
trolene, which it is easy to obtain, by submitting the alcoholic 
tincture to distillation. By the action of alcohol, it is impos- 
sible to remove all of the petrolene from the bitumen, as the 
bitumen in a measure loses its fluidity when the solvent 



*Weight of flask full of air 78.143 gms. Bar. 745 mm. 

Weight of flask full of vapor 7S.280 gms. Th. 21.2 

Capacity of flask at 21 2.297 c. c. Pres. .728 mm. 

Air remaining in flask 20 c. c. Ther. 21.2* 

Temperature of vapor 310 mercurial thermometer. 



MEMOIR UPON COMPOSITION OF BITUMENS. 95 

action of the alcohol diminishes. The distillation of the bitu- 
men at a constant and sufficiently elevated heat, gives results 
no more satisfying. After different essays, the least that I 
have employed to deprive the bitumen of its volatile principle 
consists in an exposure to a temperature of about 250 in a 
Gay-Lussac's oil bath until there is no longer loss of weight. 
This method is prolonged ; it is necessary to heat during 45 
to 50 hours, even when operating upon a gramme of material.* 

The solid principle of the bitumen which I obtained by 
this method is black, very brilliant; its fracture conchoidal ; 
it is heavier than water. Toward 300 it becomes soft and 
plastic. It decomposes before it melts. It burns after the 
manner of resins, leaving a very abundant coke. When the 
fixed principle has been extracted from a bitumen, preferably 
purified by ether, it leaves no residue after its combustion. 
As this body possessed all the characteristics of asphalt, of 
which it forms moreover the essential part, I named it as- 
phaltene. 

0.299 of asphaltene burned with oxide of copper gave: 
Carbonic Acid. Water. Carbon. Hydrogen. Oxygen. 

0.814 0.268 0.750 0.099 0.148 

This composition is represented by the formula: 

C 40 H 32 O 3 or by C 80 H 64 O 6 

which seems to indicate that asphaltene is the result of the 
oxidation of petrolene. 

Asphaltene is insoluble in alcohol ; ether, fatty oils, and 
essence of turpentine dissolve it. It is the same with petro- 
lene. 

The bitumen of Bechelbronn can be considered as a mix- 
ture of petrolene and asphaltene; that is at least a deduction 
from its analysis. 

The bitumen analyzed had been purified by ether. 

Carbonic Acid. Water. 

I. 0.357 gave 1.125 0.360 

II. 0.385 gave 1.211 0.400 

I. II. 

Carbon 0.871 0.870 

Hydrogen 0.113 0.112 

Oxygen 0.016 0.018 

*By this method it is impossible to weigh the two principles of the bitu- 
men; at that temperature a part of the petrolene becomes oxidized and 
passes to the solid state, or asphaltene. 



96 SOLID BITUMENS. 

This composition seems to prove that the bitumen of 
Bechelbronn contains : 

Petrolene 0.854 

Asphaltene 0.146 

On that supposition, one should have : 

Carbon 0.868 

Hydrogen 0.112 

Oxygen 0.020 

Whilst I have not analyzed the bitumen of Lobsann, I 
have, however, proved that it contains the two principles that 
I have found in that of Bechelbronn. 

In conclusion, it is seen that the glutinous bitumens may 
be considered as mixtures, probably in all proportions, of two 
principles, each of which has a definite composition. One of 
these principles (asphaltene) fixed and solid, approaches as- 
phalt in its nature. The other (petrolene) liquid, oily and 
volatile, resembles in some of its properties, certain varieties 
of petroleum. It may, then, be conceived that whilst the con- 
sistency of bitumen varies, it may be said to infinity; it suf- 
fices that one or the other of the two principles dominates the 
mixture, thereby giving such or such a degree of fluidity. 

A soft bitumen can always be converted to a harder va- 
riety by volatilizing by heat a portion of the liquid principles ; 
it is thus that the Indians of Payta render fit for use in paying 
their vessels a bitumen naturally too fluid for that use. 

The analogy that exists between asphaltene and the as- 
phalt of the mineralogists leads me to ascertain if that an- 
alogy is sustained by its composition. As a consequence, I 
have submitted the asphalt of Coxitambo to analysis, which 
can be considered as a type of the species. The asphalt of 
Coxitambo has a largely conchoidal fracture; it is very 
smooth to the touch (il possede un grand eclat, on le 
prendrait) ; it is of a black color and is brilliant like obsidian. 
Its density is 1.68. The asphalt of Coxitambo dissolves with 
difficulty in petrolene and the fatty oils. With this difference 
only, which appears to prove the great cohesion of natural 
asphalt, the characters of the two substances are identical. 

The asphalt of Coxitambo has been reduced to powder 
by means of a file. In two experiments I have found that its 
combustion left 0.016 of slightly ferruginous ash. 



MEMOIR UPON COMPOSITION OF BITUMENS. 



97 



0.307 of asphalt (deduction made for ashes) gave upon analysis: 
Carbonic Acid. Water. Carbon. Hydrogen. Oxygen 

0.819 0.261 0.750 0.095 0.155 

This composition nearly approaches, as may be seen, that 
of the asphaltene extracted from the bitumen of Bechel- 
bronn.* 



*Ann. de Chem. et de Physique (2), Ixiv, 14]; Jour. Franklin Institute 
xxiv, 138; New Edinburg Philos. Jour., xxii, 97. 



CHAPTER IX. 

THE USE OF THE WORDS PETROLENE, 
ASPHALTENE, ETC. 

This research of Boussingault was of great value at the 
time it was made, but modern methods have superseded 
those employed by him, and the investigation that he made in 
1837 now possesses only historic value, were it not that the 
words petrolene and asphaltene, which he coined, and other 
words, have in recent years been introduced into the discus- 
sion of the chemistry of bitumen with new meanings, the 
value of which I shall further discuss. 

The persistent use of the word retene, or retine, and 
more especially of the words petrolene and asphaltene, in cur- 
rent literature relating to solid bitumens and bituminous min- 
erals, leads me to offer a protest against their further use, 
with reasons therefor somewhat in extenso. 

The prominent position which Mr. Edward J. De Smedt 
has held in reference to asphalt paving in the United States 
has given his opinions great weight among those engaged in 
that industry. In 1893 he published in Paving a remarkable 
paper, which he said was designed "to open a discussion and 
investigation in regard to the required qualities of asphalt to 
form the best, pavement." After making statements in ref- 
erence to bitumens in general, he proceeded to make a few 
rather sweeping assertions, which may be carefully consid- 
ered. He says : "Bitumens are generally composed of three 
different hydrocarbons: (i) retine, (2) petrolene, (3) as- 
phaltene. The knowledge of these compounds is due to the 
important investigations of Le Bel and Muntz." "Retine C, 
78.84; H, 10.22; S, 10.78 is soluble in alcohol; submitted to 
heat, it gives off hydrogen sulphuret, marcaptan, and liquid 
hydrocarbon, and some coke is left. This compound is not 
desirable in asphalt. 

"Petrolene C, 80.60; H, 10.20; S, 9.20 is soluble in 
ether, and is the mort important and desirable compound in 



USE OF WORDS PETROLENE, ASPHALTENE, ETC. 99 

asphalt for paving purposes, since it is the compound which 
gives the viscous adhesive qualities to asphalt. 

"Asphaltene C, 78.00; H, 8.83; S, 12.89 is not soluble 
in alcohol or ether, but is soluble in chloroform and in bi- 
sulphide of carbon. It is this compound which gives hard- 
ness to asphalt, and the more asphaltene an asphalt contains, 
the more brittle and hard it is. So an excess of asphaltene is 
detrimental in asphalt employed for paving purposes."* 

As the technical considerations involved in De Smedt's 
paper were met in a masterly manner by Captain Dolphus 
Torrey in a paper published in Paving in March, 1894, no 
further reference to that aspect of the subject will be made. 
De Smedt was very unfortunate in his manner of conduct- 
ing the discussion, and it soon fell for want of cohesion. 

When De Smedt's paper was published, I was in Cali- 
fornia and was not reading Paving. I was, however, soon 
brought in contact with the practical effects of this publica- 
tion. As chemist to the Union Oil Co., of California, I was 
asked to determine the amount of retene in their products, 
and in correspondence I began to receive memoranda of de- 
terminations of retene. For many years the name retene had 
been applied to a crystallizable body soluble in alcohol which 
was derived from several varieties of fossil resin. As it is 
crystallizable, its formula had been carefully determined to 
be C 18 H 18 or some other multiple of CH. A great number 
and variety of different compounds derived from it had also 
been analyzed. There has been no question about the com- 
position and relations of retene for years as described in the 
general and periodical literature of chemistry. When I was 
asked to determine the amount of retene in an asphaltic 
residuum from California petroleum, and learned that a great 
many determinations of retene were being reported as made 
from asphaltum from many localities in different parts of the 
world, I began to wonder what had happened. 

At last a prospective purchaser of California products 
requested us to ascertain the amount of objectionable retene 
contained in our material, and I set to work to make the de- 
termination. I had previously learned that methyl alcohol 



*Paving and Municipal Engineering, Nov., 1893, p. 206. 



I0 o SOLID BITUMENS. 

dissolves a certain percentage of our product, ethyl alcohol 
dissolves more, and amyl alcohol still more. By prolonged 
boiling in 95 per cent ethyl alcohol nearly as large a percent- 
age was dissolved as in ethyl ether or petroleum ether. No 
crystallizable body could be obtained from any of these solu- 
tions, and I discovered that by varying the strength of the 
alcohols and the temperature at which they acted, the pro- 
portion of the residuum dissolved could be varied indefinitely. 
Further experiments upon crude California and other as- 
phaltums gave similar results. 

Later, I was asked by a friend, who was in correspond- 
ence with a 'chemist in regard to retene, or retine, I don't 
know which, if I had made any determinations of that con- 
stituent of asphalts. I related the facts as given above and 
suggested that the correspondent be asked, if he had obtained 
any crystallizable retene from any asphaltum, to tell how he 
did it. He replied that he had never determined retene, nor 
had he ever obtained a crystalline compound from any alco- 
holic solution of asphaltum. This experience confirms my 
own. 

As to the word retine, I have made an exhaustive search 
of the dictionaries of several modern languages, as well as 
English, and can find only one word w r ith that spelling. That 
is the French word which is equivalent to our word retina, 
as applied to the eye. 

If I understand De Smedt, he refers to the researches of 
Le Bel and Muntz as his authority for what he says regard- 
ing retene, or retine. I have never seen any memoir, by 
either or both of these gentlemen, wherein any reference is 
made to any such substance, or in fact, to any alcoholic solu- 
tion obtained from bitumen. 

Captain Torrey has written quite in extenso upon the al- 
cohol soluble from Trinidad pitch.* All that he has pub- 
lished upon the subject is to be found in Paving. He has 
very carefully conducted a large number and variety of ex- 
periments upon this alcohol soluble. He has discovered and 
recognized the differences produced by varying the strength 
and temperature of the alcohol, and he seeks to counteract 



*Paving and Municipal Enginering, 1894. 



USE OF WORDS PETROLENE, ASPHALTENE, ETC. ioi 

their disturbing influence by what he calls a time limit. He 
allows the alcohol to act in exact periods of time, which he 
seems to think will give exact results. I do not think he can 
escape the relations of strength and temperature in any such 
manner, nor do I see any occasion for it, unless the petro- 
leum ether soluble can be divided by using absolute alcohol 
at some fixed temperature. What is wanted is an absolute 
factor that can be repeatedly determined in the same speci- 
men within reasonable limits; or, in language used by Dr. 
S. P. Sadtler, "What is wanted is a study of the action of a 
series of solvents of fixed purity upon different natural bitu- 
mens."* 

One curious practical illustration of the use which has 
been made of this name is found in an "Asphalt Hand-Book," 
issued by the Standard Asphalt Co., of California. Dr. F. 
Salathe made an examination of their crude asphalt, and find- 
ing that acetone would dissolve more of it than petroleum 
ether, he made an acetone soluble and called it "petrolene 
(retenoid)." The portion insoluble in acetone he called "as- 
phaltene (retine)." He further gives the "combined sulphur 
(chemically held in bitumens)" as 0.73 per cent. What mean- 
ing did Dr. Salathe attach to the word "retine" as used here? 
De Smedt's retine had 10.78 per cent of sulphur and his as- 
phaltene has 12.89 P er cent. Did he intend that these sub- 
stances are practically identical? Moreover, De Smedt's 
petrolene has 9.20 per cent of sulphur; therefore, according 
to De Smedt, the California asphaltum should contain : 

Per cent. 

Petrolene ' 67.50 Sulphur 6.21 

Asphaltene 32.50 Sulphur 4.18 



100.00 10.39 

Dr. Salathe reports the content of sulphur to be 0.73 per 
cent. No more striking illustration can be found of the use 
of words that have no meaning. 

So far as I am acquainted with the literature of asphal- 
tum, it is not clear who first applied that name petrolene to 
that portion of asphaltum that may be soluble in ethyl ether 
or petroleum spirit. In the exhaustive work of Alfred H. 

"Journal of the Franklin Institute, 149, 29. 



ioj SOLID BITUMENS. 

Allen, upon "Commercial Organic Analysis*' (Vol. II, page 
374), published in 1886, mention is made of Boussingault's 
separation of asphaltum into "petrolene" and "asphaltene." 
but no further reference to the use of these names is made. 
It is possible that De Smedt first used that method of an- 
alysis and applied the names as they have since been used, 
but apparently we are indebted to Mr. Clifford Richardson 
for their use, with their present meaning. 

Their use has proceeded of late years upon a totally er- 
roneous conception of the constitution of asphaltic minerals 
and their relation to each other. If the arbitrary use of these 
names had been confined to Trinidad pitch, and the method 
or procedure of analysis of which they form a means of ex- 
pression had been confined to the admitted determinations 
of the location of the spot upon the Island of Trinidad from 
which any given specimen came, less confusion would have 
arisen than has followed the attempt to designate many dif- 
ferent things by one name. In a general way, it may be cor- 
rectly said that there are no two asphaltums from different, 
widely-separated localities that are alike. If the same pro- 
portion to a i/iooo of i per cent is soluble in any of the sol- 
vents of bitumen, it does not establish the identity of the 
two specimens. There has been nothing approaching the 
exactness demanded in chemical science observed in the use 
of the word petrolene. Ethyl ether, petroleum ether and 
acetone have all been used as it suited the convenience of 
the experimenter, and the percentage dissolved has been called 
petrolene, and various assertions have been made concerning 
petrolene and the relative value of asphaltums containing 
much or less of it ; when at the same time the material dis- 
solved from one asphaltum is one thing, and that dissolved 
from another asphaltum is quite another thing, and 
the different proportions of material dissolved from the same 
asphaltum by different menstrua are equally different. It 
is obvious that much that has been said in reference to petro- 
lene applies with equal force to asphaltene. The names have 
been applied to various residues soluble and insoluble in 
various menstrua, and in various proportions. These residues 
possess various physical and chemical properties, and are in 
few respects identical. The name asphaltene has been used 



OP WORDS PETROLENE, ASPHALTENE, li'I'C. 103 

to designate that portion of Trinidad pitch that is alone solu- 
ble in carbon disulphide. Mr. Richardson admitted, in his 
testimony given in the Peoria trial, that carbon disulphide 
did not dissolve the bitumen in Trinidad pitch within I per 
cent, and Wallace and Whinery, on the same occasion, de- 
scribed the material dissolved in this manner as an inert sub- 
stance, without cohesion, and playing the same part in a 
paving cement as the same amount of sand. 

I have found that if Trinidad pitch be first exhausted 
with petroleum ether and then with carbon disulphide, when 
the latter solution is evaporated there remains a brilliant 
black solid that cleaves from the vessel in thin scales. These 
scales are insoluble in petroleum ether, ethyl ether or alcohol, 
melted pararfine, and in fact most of the solvents of bitumen. 
They are wholly soluble in chloroform and benzole, and par- 
tially soluble in boiling spirits of turpentine, the portion in- 
soluble appearing as a brow r n powder. If the scales are dis- 
solved in benzole and petroleum ether added in large excess, 
a brown powder is precipitated that may be collected on a 
filter. When the powder is heated it becomes black and 
coheres. The portion soluble in spirits of turpentine may be 
wholly or partially precipitated, by an excess of petroleum 
ether, as a brown powder. When the solution of that portion 
soluble only in chloroform is evaporated and the residuum 
washed in ethyl alcohol, it appears as a brown powder with- 
out cohesion. These reactions show that the black scales 
obtained by the evaporation of the carbon disulphide solution 
above mentioned consist of a mixture of two, if not more, dis- 
tinct substances. The first of these that is soluble in boiling 
spirits of turpentine is a very dense and exceedingly viscous 
fluid, possessing great tenacity, and it evidently plays a very 
important part in the cementing properties of Trinidad pitch. 
The portion that is only soluble in chloroform is a dark brown 
powder without cohesion, that does not melt when heated, 
but softens, becomes black, and at a red heat is decomposed; 
giving off a white vapor which takes fire and burns, leaving 
a carbonaceous residue that continues to burn at a red heat, 
leaving a small amount of ferruginous ash. It contained 5.87 
per cent of sulphur. 

The chloroform soluble is not a constant constituent of 



104 SOLID BITUMENS. 

asphaltum. Many asphaltums have not a trace of it ; others 
have only a trace, while in others still, the percentage is very 
small. In those asphaltums in which the chloroform soluble 
is wanting, the percentage of turpentine soluble is often very 
small. There are no physical properties that serve to dis- 
tinguish these asphaltums to the eye. The asphaltum that 
contains only a trace of chloroform soluble and but a small 
percentage of turpentine soluble may be in appearance a bril- 
liant black, brittle solid, ot to be distinguished by the eye from 
one that consists of from one-third to one-half of chloroform 
soluble. The relation of physical to chemical properties has 
not yet been determined. 

It may be that the chloroform soluble represents, in some 
instances, that portion of the asphaltum that has been in 
some manner deprived of its hydrogen. This condition is not 
necessarily brought about by weathering, although it cannot 
be denied that weathered asphaltums almost invariably yield 
a comparatively large percentage of choloroform soluble. The 
following analysis of materials from the deposit at Trinidad 
furnishes a remarkable example of this fact. In the follow- 
ing table, No. I represents the average composition of the ten 
specimens of crude commercial lake and land pitch, analyzed 
by Miss Laura A. Linton. No. 2 is the average composition 
of two specimens of alteration products of Trinidad pitch, 
one of which came from the lake, and the other from outside 
of it. I have also similar material from the weathered por- 
tions of asphalt veins in California. 

No. 1. No. 2. 

Per cent. Per cent 

Petroleum ether soluble 34.612 20.306 

Turpentine soluble 12.375 17.843 

Chloroform soluble 5.757 13.968 



Total bitumen 52.744 38.981 

Organic material not bitumen 11.098 9.706 

Mineral matter 36.160 38,175 



Total bitumen soluble in petroleum ether 65.660 38.981 

Total bitumen soluble in turpentine 23.391 34.195 

Total bitumen soluble in chloroform 10.925 26.824 

The material of which the analysis is given in column 

No. 2 may be what Mr. Richardson has called "chocolate 



USE OF WORDS PETROLENE, ASPHALTENE, ETC. 105 

pitch."* It is a light brown, pulverulent solid, in form some- 
what columnar, like starch, and just as easily rubbed into a 
powder between the fingers. It contains nearly three times 
the percentage of chloroform soluble that occurs in the aver- 
age commercial pitch. Somewhere between the chloroform 
soluble of 10.925 per cent, which is found in the average com- 
mercial pitch, and the 26.824 per cent found in this alteration 
product, the Trinidad pitch loses its tenacity and becomes 
friable. Of course, as the chloroform soluble is increased, it 
must be at the expense of the other ingredients. The petro- 
leum ether soluble in this case is only about one-half the pro- 
portion given in colume No. I, the ratio being 38.981 :6$.66. 
The ratio of the chloroform soluble to the total bitumen is, 
in No. i, 1 19. 163, and No. 2, I 12.789. The investigation of 
these problems has only just been entered upon, but it is a 
research of vast importance, and must in time command at- 
tention. 

When these figures were first developed, from the re- 
sults of Miss Linton's analytical work, it was hoped that 
some satisfactory explanation of the peculiar properties of 
glance pitch might be deduced. The claim that glance pitch 
is geologically old pitch is found to be entirely erroneous. 
The following figures show the compositions of five pitches, 
all of which are supposed to be Cretaceous or older: 



Per cent of petroleum ether soluble in total bitumen.... < 



No. 1, 25.4605 

' 2, 35.0870 
' 3, 38.0300 
' 4, 49.9590 
' 5, 51.0430 
' 6, 8.5106 



Nos. 2, 5 and 6 are very brilliant glance pitch ; the others 
are equally hard, but not as brilliant. The chloroform solu- 
ble varies in these from less than i per cent in No. 6 to 32.5 
per cent in No. 4. Just as brilliant and hard glance pitch as 
any of these, I know to be a melted tertiary asphaltum, of 
which more than 75 per cent is soluble in petroleum ether. 
Such discordant results, obtained from such a large number 
of asphaltums from widely different localities, have confirmed 
the opinion that the peculiar properties of glance pitch do not 



'See Clifford Richardson, Journal Soc. of Chem. Ind., xvii, 14. 



106 SOLID BITUMENS. 

depend upon chemical composition, but are the result of the 
melting of the asphaltum. 

The term "glance pitch," is therefore, no less to be dis- 
carded. While retene or retine are terms for which no raison 
d'etre can be discovered, petrolene, asphaltene and glance 
pitch, are terms that once had meanings which are now out- 
grown. The use of all these terms should therefore be 
omitted and avoided. 

In the article published in the March number of Paving 
for 1894, Captain Torrey says, in reference to the use of the 
names retine, petrolene and asphaltene : "With the present 
knowledge of them, it would be better not to use these mis- 
leading names, but others more appropriate." In this opinion 
I fully agree, and w'ould add that for some time past I have 
sought to discard them, and to report the percentage soluble 
in petroleum ether and other solvents as "the petroleum 
ether soluble," and not as petrolene, etc. For these reasons 
these terms will not be further used or discussed in this work. 



CHAPTER X. 
THE ULTIMATE ANALYSIS OF SOLID BITUMENS. 

Solid bitumens consist of a great variety of mixtures of 
complex compounds of carbon and hydrogen together with 
compounds of carbon and hydrogen with oxygen, sulphur and 
nitrogen. Nearly or quite all natural solid bitumens contain 
organic salts of iron and alumina resembling the organic salts 
of alumina found in amber and coal. 

The ultimate analysis of such an exceedingly complex 
mixture of substances presents some difficulties. 

The carbon and hydrogen may be determined with War- 
ren's apparatus for combustion in oxygen gas, using proper 
precautions with reference to the sulphur present, or any 
other of the ordinary processes for elementary analysis. This 
is a well tried method the value of which has been thoroughly 
tested by Mabery and others. I have repeatedly obtained 
results by its use that left nothing to be desired.* 

Recently Porter R. Shimer has described a method for 
determining carbon and hydrogen in a platinum crucible. f 

Oxygen is usually determined as a residual difference 
a method of determination, open to grave criticism. For 
many years I have doubted the existence of oxygen in either 
natural or artificial hydrocarbon nuclei, that are constituents 
of solid bitumens. So far as my observation has gone, both 
in the field and in the laboratory, atmospheric oxygen, espe- 
cially when dissolved in rain water as a natural phenomenon, 
or oxygen, when made to react with bituminous materials in 
the laboratory, does not enter the hydrocarbon nucleus by sub- 
stitution for hydrogen, but substracts hydrogen from the 
nucleus, forming water which escapes, leaving a condensed 
molecule which contains proportionately more carbon and 



*The original description of Warren's apparatus was published in 1864 
and 1S66 in the Memoirs of the American Acad. Science, Boston, the Ameri- 
can Journal of Science and the London Chemical News. 

tPorter R. Shimer, Jour. Am. Chem. Soc., xxi, 557; xxv, 237, 997. 

107 



108 SOLID BITUMENS. 

less hydrogen, remaining a hydrocarbon and not an oxyhy- 
drocarbon. 

Sulphur has been recognized as a constituent of bitu- 
mens for many years. In the anonymous abridged transla- 
tion of Boerhaave's Elements of Chemistry, published in Lon- 
don in 1732, p. 18, before referred to, under the head of sul- 
phurs, are described "Brimstone, orpiment, petroleum, naph- 
tha, asphaltum, Jewish pitch, pissasphaltum, jet, litbrant- 
brax, amber and oil of earth." Judging from the detailed 
description, some of these substances are products of the 
imagination, but the classification shows that certain sim- 
ilarities were early recognized. 

Those who have analyzed bitumens without proper at- 
tention to the presence of sulphur, have until recently at- 
tributed to the presence of oxygen a residual difference that 
should properly have been credited wholly or in part to sul- 
phur. Again, after the presence of sulphur as an almost 
constant constituent of natural solid bitumens had been ad- 
mitted, a number of determinations of sulphur have been pub- 
lished that have been made by methods not always reliable, 
the results of which have led to some confusion and to state- 
ments concerning the sulphur content of bitumens that ap- 
pear to me somewhat exaggerated. In illustration it has been 
stated that some solid natural bitumens contain 10 per cent 
or more of sulphur, when it is easily demonstrated that one 
part of sulphur melted into nine parts of a bitumen free from 
sulphur, produces a substance wholly unlike any natural bitu- 
men. Nevertheless, without doubt sulphur has played a very 
important part in the formation of many solid bitumens, that 
are in many instances largely the result of the action of sul- 
phur upon fluid or semi-fluid bitumens. Sulphur burns out 
the hydrogen from bitumens, and this reaction may proceed 
slowly at ordinary temperatures or rapidly at higher temper- 
atures. It is not necessary that the sulphur should be free. 
It has long been known that sulphates are deoxidized when 
brought in contact in solution with dead organic matter. If 
the organic matter has already been distilled into bitumen, 
the reaction proceeds through double decomposition, a car- 
bonate of the base being formed and hydrogen sulphide, free 
sulphur, and a sulphur substitution compound remaining as 



ULTIMATE ANALYSIS OF SOLID BITUMENS. 109 

a part of the bitumen.* In proof of this latter statement we 
have the direct evidence furnished by Mabery's researches 
upon Lima petroleum. This is a paraffine petroleum, and the 
sulphur compounds isolated are paraffine derivatives. As al- 
most nothing has been proved concerning the sulphur com- 
pounds of solid bitumens, there is very little upon which to 
base any general conclusions concerning them. The sulphur 
content of solid bitumens is at present an open question. 

C. M. Warren in March, 1865, published in the Proc. 
Am. Acad. Sciences a paper "On a New Process for the De- 
termination of Sulphur in Organic Compounds, by Combus- 
tion with Oxygen Gas and Peroxide of Lead."f 

Of the merits of the process I have no practical experi- 
ence. 

Until recent years few, if any, investigators who have 
written upon this subject have a word to say concerning the 
method that they used for determining the sulphur; conse- 
quently I have never had any other instructor than experience. 
This experience began several years ago while in southern 
California, in an attempt to establish, at the request of the Pat- 
ent Office examiners, specific differences between a solid as- 
phaltic residuum obtained from California petroleum, the same 
oxidized by prolonged action of air, and also by treatment with 
sulphur. Nearly all of this work was carried on in association 
with Dr. Frederick Salathe, who said he had examined a large 
number of natural and artificial bitumens for sulphur. The 
residuum and sulphurized residuum were tested for sulphur 
by boiling with fuming nitric acid in a flask with an inverted 
condenser, and no sulphuric acid was found in the liquids. 
This method of testing was not then further investigated. 
Other reactions showed that a compound was formed, which; 
when oxidized with nitric acid, produced styphnic acid, which 
is a trioxynitrobenzol a compound not only interesting, as 
showing the action of the sulphur, but also as showing that 
the residuum consisted of benzols. Neither transmitted air 
nor direct oxidation with nitric acid converted any portion of 
the sulphurized residuum into styphnic acid. Treatment of 



*Geolog. and Chem. Essays, T. S. Hunt; pp. 87, 99, 145, 163 and 230. S. 
F. & H. E. Peckham, Jour. Soc. Chem. Ind., Dec., 1897. 
tAm. Jour. Science, xli, Jan., 1866. 



110 SOLID lU'I'L'MlLXS. 

the residuums by deflagration with XaCO., and KXO.. showed 
sulphur in the residuum, but only a trace in the same after 
treatment with sulphur at a temperature of 400 F. At that 
temperature the sulphur almost fully burned out with hy- 
drogen, and the bitumen was left dryer and more brittle. 
Later, I had occasion to determine the sulphur in various 
bitumens, and recourse was had to boiling with fuming nitric 
acid, with an inverted condenser. After repeated attempts it 
was discovered that no quantitative determinations of any 
value could be made in this way. Addition of potassium ni- 
trate, chlorate, or permanganate was of no avail, and I finally 
abandoned all attempts in this direction. I believe I have 
tried every method for the determination of sulphur except 
the bromine method, and that has never appeared to be prac- 
ticable with solids. Nor has the method of Carius, which I 
mention here, for fear that by its omission I might be mis- 
understood. The method which I finally adopted, is one that 
was used for the determination of sulphur in the Pacific Coast 
coals. (See Geology of California, vol. II., The Coast Ranges, 
App., Cambridge, Mass., 1882, p. 45.) It is susceptible of 
great accuracy if conducted with care. Two gms. of the bitu- 
men are intimately mixed in a mortar with 16 gms. each of 
pure, dry NaCO 3 and KNO 3 and the whole projected in small 
portions at a time into a 2-oz. platinum crucible, heated to 
dull redness, or no hotter than is necessary to cause the mass 
to deflagrate. Experience will soon teach the manipulator 
how best to conduct the operation. After deflagration and 
complete fusion, the mass is dissolved in water, hydrochloric 
acid added, and the solution either evaporated for removal of 
silica or immediately filtered, and the sulphuric acid precipi- 
tated in the hot acid solution. The barium sulphate is washed, 
dried and weighed with the usual precaution. 

I repeat that this method is susceptible of great accuracy 
if conducte' 1 with care, and it has the advantage of bringing 
into solution all of the mineral matter contained in the bitu- 
men. 

It was, however, criticized by E. H. Hodgson in the 
Journal Am. Chem. Soc., November, 1898, in a paper in which 
the results obtained by several methods used upon the same 
materials were compared. In the Jour. Am. Chem. Soc. for 



ULTIMATE ANALYSIS OF SOLID BITUMEXS. m 

September, 1899, ^- l r - a "d H- E- Pcckham replied to the 
criticism of Mr. Hodgson as follows : 

The paper is evidently intended to be a description of a 
fair comparative test of the value of the several methods used 
for the determination of sulphur in the different varieties of 
bitumen examined. 

We wish to call attention to a number of unrecognized, 
or at any rate, unmentioned conditions, which, in our opinion, 
render the results, given by Mr. Hodgson, variable, and to 
some extent unreliable. 

Of the specimens selected for analysis, it is to be said, 
that the two specimens called "Trinidad Lake" and "Trinidad 
Lake refined'' are very peculiar substances. They, in com- 
mon with all other Trinidad pitch, consist of a mixture of 
bitumen, mineral matter, organic matter that is not bitumen, 
and a considerable proportion of ferric and aluminic oxides, 
that are combined with organic radicals to form complex 
salts. There are sound reasons for believing that some of 
the sulphur is free, some of it in combination with iron as 
pyrites, in an extremely minute state of division, and some of 
it in combination as thio-salts, in which it performs a linking 
rather than saturating function. 

There can be no question that the action of nitric acid 
on this complex mixture of various substances results in the 
formation, not only of sulphuric oxide, but-of other oxides, 
of alumina and iron, that will almost certainly form double 
barium salts with sulphuric acid, that are nearly or quite as 
insoluble as pure barium sulphate, and consequently follow, 
or accompany the barium sulphate^ even to the final weighing. 

The specimen denominated "Trinidad crude" and further 
described as "crude asphalt from Hadley's diggings, about 
one mile from Trinidad Lake; it is known as 'iron pitch/ be- 
ing the hardest asphalt found in Trinidad," is not asphalt at 
all, but is a residue from the natural distillation of the pitch 
by jungle fires, found in small masses, and in small quantity, 
all over the deposit, both within and without the lake, and it 
is uniformly rejected as rubbish. It has been subjected to 
such a temperature that all of the water has been expelled, 
and the whole mass melted and brought to a condition of 
semifluidity. Apparently the sulphur is in part expelled, and 



112 SOLID BITUMENS. 

that which remains is evidently brought into such a condition 
that the nitric acid process fails to produce the reaction essen- 
tial to the formation of double salts, as the results of the 
analyses by the four processes used by Mr. Hodgson are 
essentially alike. The results obtained from Cuban, Alcatraz, 
and California asphaltum are evidently subject to the same 
criticism as the Lake pitches, in a less degree. 

The deflagration method, as described in Mr. Hodgson's 
paper, is not the method used by the authors. We never used 
a porcelain crucible; first, for reason of its form, and second, 
for reason that the fluxes used will react with the porcelain, 
making it impossible to determine the iron, alumina, and 
silica in the assay. 

We have modified to a slight degree our method of pro- 
cedure, as experience has suggested, until finally we have 
weighed out such an amount of the assay as will represent 
about 0.5 gram of bitumen. This is very thoroughly mixed 
with 15 grams each of pure dry sodium carbonate and potas- 
sium nitrate. The salts are first thoroughly pulverized and 
mixed in an unglazed porcelain mortar. Two-thirds of the 
mixture are then removed to a sheet of glazed paper. The 
assay is mixed in the mortar with the flux in the most thor- 
ough manner and then removed to a second sheet of glazed 
paper. The mortar is carefully rinsed with the remaining 
flux in two successive portions. The whole of the flux and 
assay are brought to a uniform mixture on the glazed paper. 
The mixture is then brought, small portions at a time, into a 
2-ounce platinum crucible, heated to dull redness. No fusion 
with a blast-lamp is necessaiy, as the assay is in quiet fusion 
when the last portion has deflagrated. A large excess Of flux 
lessens the violence of the combustion and also lessens the 
liability to loss by spattering. 

The contents of the crucible are then dissolved by allow- 
ing it to remain covered with water in a beaker, preferably 
over night. When the solution is complete, the crucible is 
washed off and the contents of the beaker rendered acid with 
hydrochloric acid. The solution is evaporated to dryness 
over a water-bath, the silica dehydrated, moistened with hy- 
drochloric acid, treated with water and the silica filtered off, 
io-nited, and weighed. The solution is rendered alkaline with 



ULTIMATE ANALYSIS OF SOLID BITUMENS. 113 

ammonia, boiled until the excess of ammonia is removed, and 
the precipitate of iron and alumina dried and weighed as 
usual. The iron may be found in another portion with potas- 
sium permanganate and the alumina determined by differ- 
ence. Lime may be determined as oxalate if desired. 

The solution, freed from silica, iron, alumina, and lime, 
is brought to a boil, acidulated with hydrochloric acid, and 
the sulphuric acid precipitated with barium chloride, added in 
small portions at a time from a pipette. This method for the 
determination of sulphur is susceptible of great accuracy, if 
conducted with care. It requires great care from the begin- 
ning to the end. Mr. Hodgson's results do not indicate great 
care, they are not sufficiently concordant. 

We have not found the slightest difficulty in bringing 
out concordant results to the second place of decimals, and 
sometimes to the third. The method has also been proved 
presumably correct by reason of determinations made by 
first estimating the sulphur in a very pure asphalt and then 
in the same asphalt to which a weighed quantity of pure, dry 
sulphur had been added. The results showed the amount of 
sulphur in the pure bitumen plus the amount of pure sulphur 
added. 

It is to be noted that in materials exceptionally low in 
sulphur, it is necessary to take a larger portion than is 
usually found advisable in the use of this process, 'and when 
so much of the asphalt is burned it becomes absolutely neces- 
sary to use a larger proportion of the flux, otherwise some 
of the assay will escape oxidation. 

It has not yet been shown that mercaptans and similar 
sulphur compounds exist as constituents of crude bitumens 
in such amount as to be worthy of consideration in this con- 
nection. This method is not recommended as superior to the 
method of Carius in ultimate research, but is recommended 
for the determination of sulphur in solid and semisolid bitu- 
mens for technical purposes, as very much simpler and more 
rapidly executed. 

As the next step in the evolution of a reliable process for 
the determination of sulphur in solid bitumens we have in the 
Jour. Am. Chem. Soc. for September, 1905, p. 1188, a paper 
on an "Inner Crucible Method for Determining Sulphur and 



114 SOLID BITUMEXS. 

Halogens in Organic Substances," by S. S. Sadtler. The 
author states : 

"To all workers in organic chemistry who have to make 
determinations of sulphur and halogens in research or com- 
mercial work, the use of the Carius furnace is almost always 
found to be troublesome. It has always been so to the writer, 
and after many plans to avoid its use, he devised the way here 
described. 

"The general idea does not seem to be a new one, as Dr. 
Edgar F. Smith said in discussion upon an unpublished paper 
read by the writer before the Philadelphia section of this so- 
ciety, that he had used an inverted inner crucible with caustic 
lime as a reagent to determine chlorine in organic substances 
when a student. More recently Shimer* described an inner 
crucible method for determining carbon in steel, etc. The 
writer tried inverting small platinum and porcelain crucibles 
in large platinum crucibles, but with sulphur compounds con- 
taining volatile constituents the oil not only began to distill 
before the absorbing layer of the reagent became sufficiently 
heated to take up the sulphur, but also came off too fast. 

"Successful results even with fairly volatile oils contain- 
ing sulphur were finally obtained by modifying the inner cru- 
cibles so as to meet the requirements. It was made at first of 
sections of glass combustion tubing, the idea being to keep 
the charge to be analyzed as far as possible from the points 
of application of the heat, and to have a relatively poor con- 
ductor of heat, which was readily obtained with glass. The 
charge was put in the rounded end, which had been drawn 
out to seal it and packed with Eschka mixture. This made 
a fairly satisfactory apparatus, for, while the absorbing mix- 
ture became red hot, the oil was only gradually vaporized. 
It was found, however, that the glass was acted upon by the 
alkaline mixture and sulphur seemed to be taken tip at times 
in an adhering mass in one determination and given off in 
another. An ordinary 2o-gram platinum crucible was used 
for the outer crucible. The inner crucible of glass, however, 
was not considered practicable and a cylinder of platinum 
closed at the upper end was tried, and it was found that the 
Eschka mixture expanded with heat and lifted the cylinder. 

*Chem. Eng., November, 1904. 



ULTIMATE ANALYSIS OF SOLID BITUMENS. 115 

The following apparatus was, therefore, tried after other in- 
termediate attempts, and found to be satisfactory. 

"The outer crucible is made with straight sides like an 
inverted truncated cone with a tightly fitting lid. In the 
bottom is a cylindrically shaped indentation so as to extend 
the highly heated zone into the inner crucible. 

"The inner crucible was made with sides very nearly 
parallel to the outer crucible when inverted within it. Small 
rings of platinum were soldered to the wide, closed end, so 
as to keep it centered with respect to the outer one. 

"The open end is made as thin as possible so as to min- 
imize the tendency to conduct heat. The edge fits about 
midway between the walls of the central indentation and the 
outer crucible. 

"The method of procedure varies somewhat with the 
material for analysis. With solids, careful insulation of the 
two crucibles is not necessary. With liquids, especially those 
containing sulphur, careful insulation is requisite, and with 
very volatile ones, such as carbon disulphide, it is necessary 
to fill them into small capillary bulbs such as are used for 
sealed tube combustions. 

"An important difficulty in the way of getting accurate 
results with this method was the puffing of the Eschka mix- 
ture, and the author found that the chemically pure light 
magnesia he was using contains 12 per cent of water, and 
when this was driven off, and carefully dried, sodium car- 
bonate was used, that lifting the crucible and puffing ceased. 
The mixture was made up of equal weights of dried magnesia 
and sodium carbonate instead of 2 to i. 

"The substance is first weighed into the inner crucible, 
which is placed open end up on the balance pan. It is found 
desirable to take the minimum weights which will give final 
precipitates suitable for weighing. Thus about i gram of 
sulphur compound containing i per cent sulphur is taken. 

"An amount of a halogen compound containing 1/20 
gram of actual halogen, depending somewhat upon the one 
in question, and about the same amount of phosphorus con- 
taining substance. 

"Enough mixture is then put in to absorb the substance, 
when it is a liquid, and then filled nearly to the top with mod- 



Il6 SOLID BITUMENS. 

erate tamping. Plain ignited magnesia is then put in level 
with the top, so as to keep the soda away from the platinum, 
as the platinum on the bottom of the crucible is attacked by 
the hydrate of soda which is formed at the high temperatures, 
or by some compound with reducing gases. 

"Freshly ignited white asbestos is then put around the 
raised portion of the bottom of the outer crucible to keep the 
two crucibles from being in actual contact. It is then low- 
ered over the inner crucible and the two crucibles inverted. 
A layer of magnesia mixture about *4 mcn deep is then put 
in between the crucibles. The outer crucible is then put 
through a hole in a piece of thin but fine asbestos board so 
that very little, if any, of the sides can be exposed to the 
direct action of the flame. 

"A very small pointed flame of a Bunsen burner is now 
used so that the flame is chiefly in the indentation on the bot- 
tom. If gases do not come off from the crucible in three to 
five minutes with this flame, the heat is increased, and when 
no more odor is noticeable the crucible is placed in a piece 
of asbestos having a larger hole, so that half the crucible 
may become red hot and is kept so for ten minutes. The 
flame is then withdrawn, and when cool the inner crucible is 
carefully raised and tapped, so that its contents are dropped 
into the outer one, when the carbon is burned out with a 
shield of asbestos to protect the contents from the sulphur 
gases of the flame in the case of sulphur determinations. 

"For sulphur determinations the contents of the crucible 
are washed into a beaker. Bromine is added to oxidize sul- 
phites, etc., the solution is filtered, acidified and precipitated 
with barium chloride, as in the case of determinations of sul- 
phur in coal. 

"With halogen compounds the contents are washed into 
a beaker and dissolved with pure nitric acid, the asbestos 
filtered off and the halogen precipitated by means of silver 
nitrate. The chief precaution the author (S. S. Sadtler) has 
found necessary is to bring all the contents of the charge to 
a red heat to break up any oxygen compounds of chlorine. 

"This method applies to all organic combustions of sul- 
phur, the halogens and phosphorus, but the amount taken 



ULTIMATE ANALYSIS OF SOLID BITUMENS. ny 

must be limited to take only a moderate final weight of 
barium sulphate or silver halide, such as o.iooo to 0.2500 

The Determination of Sulphur in Petroleum and Bitu- 
minous Minerals, by F. C. Garrett, D. Sc., and E. L. Lomax, 
B. Sc.,* is as follows: 

"Many methods for the estimation of sulphur in bitu- 
minous minerals have been suggested, but Hodgsonf has 
has shown that none could be trusted except that 'of Carius, 
and this method, though accurate, is very tedious. We have 
found that, by some modification in the details, the familiar 
method of heating with a mixture of sodium carbonate and 
lime or magnesia can be used even in the analysis of petro- 
leum. A convenient quantity (i. e. from 0.7 to 1.5 gm.) of 
the substance is placed in a small platinum crucible, inti- 
mately mixed with 3 or 4 gms. of a mixture of four parts 
of pure lime to one of anhydrous sodium carbonate, and the 
crucible completely filled with the lime-soda mixture. A 
larger platinum crucible is placed over the small one (mouth 
downward), the whole inverted, and the space between the 
two crucibles filled with the lime-soda mixture. The mouth 
of the crucible is covered with a thick pad of asbestos board, 
and the apparatus placed in a muffle furnace heated to bright 
redness ; the object of the asbestos pad is to protect the inner 
crucible from radiation from the roof of the muffle, and to 
insure that distillation shall not commence before the mix- 
ture in the outer crucible has time to heat up. Distillation 
commences in about two minutes, and as soon as a flame ap- 
pears the asbestos may be removed. To insure complete oxi- 
dation of carbon the roasting should be continued for two 
hours. The mixture is then brought into water, the sul- 
phides, etc., oxidized by bromine, and the solution acidified, 
filtered, and precipitated by barium chloride as usual. If the 
amount of sulphur is small it is advisable to allow the solu- 
tion to stand on the water bath for 24 hours before filtering 
off the barium sulphate." 

"It was suggested that as about 22 gms. of the lime- 
soda mixture was used, the large amount of calcium and 
sodium chlorides in the solution might affect the result. A 

*Jour. Soc. Chem. Ind. Dec. 15, 1905, p. 1212, Vol. XXIV. 

fJour. Amer. Chem. Soc. 1898, 20, 882; Jour. Soc. Chem. Ind., 1899, 77. 



Tig SOLID BITUMENS. 

solution of pure sulphuric acid was therefore prepared of 
such a strength that 25 c. c. contained 58.8 milgms. of H 2 SO 4 
or 18.4 milgms. of sulphur; 25 c. c. of this solution was added 
to 20 gms. of the mixture, and worked up as usual, when 
0.1428 gms. of Ba SO 4 was obtained, corresponding to 60.0 
milgms. H 2 SO 4 or 18.8 milgms. of sulphur." 

In reply to a letter (1906) asking what method he used 
for the determination of sulphur, Dr. C. F. Mabery replied : 
"There is only one method for the determination of sulphur 
in oils and asphalts that is reliable, and that is combustion in 
a current of oxygen and titration in alkaline solution. The only 
way to apply it is a glass tube as long as a combustion tube. 
The products are absorbed in a i/io or i/ioo normal caustic 
solution. I have had hundreds of analyses made in the last 
six months by this method. It is reliable to within a few 
hundredths of I per cent. The trouble with all fusion meth- 
ods is that volatile sulphur compounds escape as decomposi- 
tion products."* 

Lidow changes the oxidation treatment by using a sodium 
nitrate mixture. He dissolves I gm. of the bitumen with 
chemically pure ether or some other volatile* solvent, and 
mixes the solution in a mortar with 30 gms. of a mixture of 
17 parts potassium nitrate and 13 parts soda (sodium car- 
bonate?). The solvent is evaporated, the mixture projected 
into a platinum vessel of 250 to 300 c. c. capacity at a bright 
red heat and the sulphur determined in the melt as usual 
with barium chloride. According to Pellet (Zeitsch.. f. Angew. 
Chem. 1900, p. 811) it is important that the heating be done 
over a flame free from sulphur (alcohol, benzine, etc.).T 

Instead of the sodium nitrate mixture, Eschka employs a 
mixture of calcined magnesia and ammonium nitrate, a 
method which Hodgson prefers to all others for accuracy and 
convenience.^ 

Henriques combines the oxidation of the substance by 
means of nitric acid in an open vessel followed by a fusion 
with a sodium nitrate mixture, and can recommend this 



*Jour. Am. Chem. Soc. 1894. 

tJour. Russ. Phys. Chem. Ges. zu St. Petersburg, 31. p. 567; Zeitsch. 
f. Angew, Chem. 1898, p. 296. 

tJour. Am. Chem. Soc. 1898, p. 882. Zeitsch. f. Angew. Them. 1898, p. 



ULTIMATE ANALYSIS Ol : SOLU> HITUMHXS. \ iy 

method as unqualifiedly and technically the most convenient. 
One gm. of the sample to be analyzed is placed, with a glass 
rod in a small unglazed porcelain dish of 6 c. m. diameter 
and 30 c. c. m. capacity, which is then filled one-third full 
with pure concentrated nitric acid (sp. gr. 1.4) and warmed 
on a water bath. He then covers with a watch glass and con- 
tinues warming until brisk evolution of red fumes shows the 
beginning of the decomposition. The reaction under the 
watch glass should be carefully watched that it does not be- 
come too violent, in which case the dish should be removed 
from the water bath or the heat lowered. The process is thus 
kept wholly in hand. The heat is applied to the covered dish 
from time to time until the substance is wholly decomposed 
and the evolution of red fumes ceases. The watch glass is 
then removed, and wiped with small pieces of filter paper, 
which are dropped in the acid and the acid evaporated to the 
consistency of a syrup. Then a quantity of nitric acid is 
added equal to that first taken, and evaporated a second time, 
which is in all cases sufficient. 

When the nitric acid is driven off, the warm syrup is 
completely mixed with not to exceed 5 gms. finely pulverized 
sodium nitrate mixture (5 3) that must be so carefully in- 
troduced as to exclude large crystals of nitrate. 

It is left upon the water bath until no more carbonic acid 
escapes and finally there is strewn over the matted mass 
more sodium nitrate mixture before the final melting. This 
has to be done with care to avoid spattering. 

The melting dish is placed about 5 cm. above a small 
Bunsen flame, which can later be made higher, covered over 
with a second dish of the same form (concave surface down). 
The spattering will increase, but the sodium nitrate that 
strikes the cover will remain there in small particles. Under 
normal conditions the mass gradually blackens at the edges 
and can become strongly melted while the brown products of 
distillation collect on the cover dish free from sulphur. The 
duration of the melt can be diminished towards the end by 
removing the covered dish and by stirring with the glass rod 
held by crucible tongs for I to i l / 2 hours. 

After cooling, the melt is treated with boiling water and 
filtered, by which the sulphuric compounds go over into the 



120 SOLID BITUMENS. 

filtrate as alkaline sulphates, while upon the filter are found 
the metals present in the form of carbonates or oxides.* 

Xearly all asphalts contain silicon (see Le Bel and 
Muntz, Bull. Soc. Chem. (2) 17, p. 156; Le Bel, ditto, (2) 50, 
p. 3 "9), in the form or organic compounds. In practice the 
filtrate is evaporated to dryness with addition of hydro- 
chloric acid and the silicic acid becoming insoluble, is 
drenched with water and filtered off. The sulphur is finally 
determined in the form of barium sulphate as usual. 

By another procedure the asphalt is treated by melting 
with a mixture of sodium carbonate and caustic soda, and the 
sulphides present are oxidized with sodium peroxide and the 
sulphur precipitated as barium sulphate. 

v. Konek likewise uses sodium peroxide for the determin- 
ation of sulphur in bituminous and all organic bodies, and 
concludes the work by the well known sodium peroxide calor- 
imeter of Parr.f The determination in this apparatus, as 
compared with other methods, requires so short a time, that 
the process of v. Konek has been called the rapid method for 
the determination of sulphur. A detailed description of Parr's 
calorimetric researches and of his method of procedure is 
given by G. Lunge (Zeitsch, f. Angew. chemie 1901, p. 793). 

The determination of the calorific value is never applied 
to asphalts. For the purpose of determining the sulphur the 
bomb is taken from the water bath of the calorimeter, the 
cover unscrewed and finally well rinsed with cold water into 
a Becker glass of 700 c. cm. capacity. The open bomb is then 
placed in an inclined position in the Becker and in order to 
decompose the contents, 10 c. cm. of cold water are added 
thereto and the glass covered with a close fitting watch glass. 
In a few minutes the steel cylinder froths, and boiling, pours 
the greater part of its contents into the Becker glass. After 
the first strong reaction is over the hot bomb is raised out 
of the beaker with a pair of crucible tongs, placed in a small 
porcelain dish and rinsed at first with a little cold water until 
it no longer has an alkaline reaction, when the small piece of 
iron wire which serves to ignite the mixture of peroxide of 
sodium is washed out of the bomb. Wash sparingly with 



*Jour. Am. Chem. Soc. 22., 1899, p. 802. 

tJour. Am. Chem. Soc. 22, p. 646. Chem. Zentralblat, 1900. I!. 10 50. 



ULTIMATE ANALYSIS OF SOLID BITUMENS. 121 

water so that with the additions there shall be no more than 
200 c. cm. In this way the united contents of the bomb are 
estimated in the Becker glass, which, containing in solution 
sodium peroxide, sodium carbonate and sodium sulphate, will 
be found strongly alkaline, and must be neutralized with 40 
c. cm. pure concentrated hydrochloric acid, heated to boiling, 
under a watch glass, freed from any particles of carbon or 
other impurities by filtration, the boiling filtrate precipitated 
in the usual way with barium chloride, and the sulphuric acid 
found. The primary condition of the use of Na 2 O 2 in the 
determination of sulphur is, that it be chemically pure, and, 
above all things, absolutely free from sulphur compounds. 

In the determination of the sulphur content of asphalt 
by the use of the "rapid" process, the practically small quan- 
tity of the substance is weighed, by pouring it from a crystal- 
lizing dish in which the bitumen has been rendered suffici- 
ently fluid by warming it to 70 to 90. Harder asphalts are 
brought into the form of powder. Sometimes one-half the 
mass of the Na 2 O 2 is warmed in a drying oven and 0.3 to 
0.4 gm. of the melted asphalt is allowed to drop upon it, then 
mixed as well as possible and the mixture brought while 
warm into the bomb by means of a small copper funnel ; the 
second half of the peroxide serves to rinse the dish, glass rod 
and funnel, and then, after strewing the surface with o.i to 
0.2 gm. pure, dry, powdered tartaric acid, the bomb is closed 
and discharged as described. The decomposition of the con- 
tents of the bomb with water requires much circumspection, 
because the mixing of viscous substances with Na 2 O 2 is not 
possible without more or less lumpiness. Moreover, the coal 
occasioning the explosion is free from sulphur, as v. Konek 
has pointed out, because this, even with sodium peroxide, is 
much more quickly oxidized than as carbon. 

Following are the results of analysis, conducted by this 
method: 

Percent of Sulphur 

Rapid 

Method. Carius. 
1 Bitumen from Trinidad (old sample) 3.52 

2. Bitumen from Trinidad (new sample) 3.56 

3. Bitumen from Derna Tartaros, Hungary 0.5G 0.30 



122 SOLID BITUMENS. 

v. Konek commends as the chief excellence of this 
method the rapidity and consequent saving of time. In many 
cases the circumstance is naturally also of great value, that 
at the same time therewith the determination of the molecu- 
lar, calorific and heating effects, can be associated with it. 
In from 10 to 20 minutes, the sulphur content of every organic 
compound is quantitatively separated in the form of barium 
sulphate, a result that no single one of the hitherto useful 
methods for the determination of the sulphur in organic 
bodies has accomplished.* 

Mabery burns crude petroleum, asphalt, etc., in a stream 
of oxygen or air and leads the products of combustion 
through a standard solution of caustic potash. The sample 
to be examined is put in a platinum boat in a wide potash 
glass tube, burned in a stream of air or oxygen gas and the 
gas with a steady stream of carbonic acid led through into 
normal caustic potash in a tube filled with pieces of glass. 
After the determination of the combustion, by the application 
of methyl orange, an indicator not affected by carbonic acid, 
the solution is titrated back, and from the consumption of 
the normal solution, the sulphur content of the burned prod- 
uct may be calculated.! 

For determining sulphur J. Heusler, C. Engler, R. Kies- 
zling and Ohlmiiller burn the oil in a small lamp and ab- 
sorb the gaseous products of combustion in an absorbent 
fluid, like solution of permanganates (Heusler, Kieszling) 
an alkaline bromine solution (Engler) or hydro-potassium 
carbonate solution (1-20, Ohlmiiller). 

These four methods were subjected by S. Friedlaender 
to comparative tests, who found that in respect to accuracy 
the results are equally complete and reliable. A prerequisite 
is a perfect sootless combustion as well as an efficacious ab- 
sorbent for the gas. If, according to the method of Holde, 
the asphalt be dissolved in a petroleum free from sulphur, 
and burned in a lamp, then this method can also be applied 
with success to the determination of the sulphuric content 
of asphalt. 

Neither of these lamp processes is recommended for 

Zeitsch. f. Angew. Chemic., 1903, p. 516. 
tAm. Chem. Jour., 18&4, p. 544. 



ULTIMATE .IX. \l. Y SIS OI : SOI. in LUTUMENS. 



123 



solid bitumens by the author, but the process of Engler is 
given as that which in practice may be found most useful 
and refer, regarding the others, to the dissertation of Fried- 
laender. 

The sample of petroleum, or a solution of the sample of 
asphalt in petroleum, is filled into a small lamp (Fig. i). 
which is connected with the air tight cylinder C by means of 
the cork stopper K. The cork stopper bears a metal cap M. 
through which the air required for combustion is led through 




Fig. 1. Bugler's Lamp. 



the pipes and into the combustion chamber; the metal cap 
terminates in a perforated plate by which the air is equally 
distributed. Into the cylinder a glass tube G, bent at a right 
angle, is fused through which the products of combustion are 
drawn into the absorbent vessel. This vessel is half filled 
with glass beads and will hold from 20 to 25 c. cm. of the 
absorbent fluid. To the absorbent vessel is attached a 
Munich wash flask, to retain any of the absorbent fluid that 
may escape from the absorbent vessel through too rapid 
transmission of the air. The gas that is not absorbed is re- 
moved by a suction pump through the escape pipe 5". 



124 SOLID B1TUMEXS. 

At the end of the combustion, 20 to 25 c. cm. of water 
are sucked into the absorbent vessel through the cock H, and 
a minute thereafter air is aspirated through the whole ap- 
paratus and the water again drawn off; this operation must 
be repeated several times. 

According to the representation of Engler the most use- 
ful absorbent fluid is a 5 per cent solution of potassium car- 
bonate containing sufficient free bromine to give a slightly 
yellow color to the liquid, which is left to stand a few days 
in the air, as a stream of sulphur free air is passed through 
it, until it is discolored. A portion of the colorless solution 
is tested by acidulating with hydrochloric acid and precipitat- 
ing with barium chloride solution, if the presence of sul- 
phuric acid is surmised, and the remainder that is found free 
is applied to the absorption of the gases of combustion. 

At the end of the combustion the discharged fluid is sat- 
urated with hydrochloric acid, and boiling hot, is precipitated 
with barium chloride. 

Table I shows the duration and the results of the four 
methods as applied to the same petroleum :* 

Duration of Percent 
Method. Application. Combusion. of sulphur. 

Heusler 13.86 2hrs.20min. 0.0286 

Engler : 11.05 4hrs.56min. 0.0286 

Keiszling 11.71 2hrs.04min. 0.0280 

Ohlmuller 12.74 hrs. 31 min. 0.0284 

Not only can the free sulphur involved in the bitumens of 
natural asphalt, but also that combined in organic forms as 
well, be made to appear. According to Endemann, it is not 
immaterial which solvent is used for the extraction of bitu- 
mens. In treating the free sjilphur contained in residues he 
casts aside carbon disulphide and all solvents containing sul- 
phur and carries on the extraction with pure chloroform. 

The determination of nitrogen in solid bitumens is fre- 
quently a matter of much importance. 

The presence of this element in bitumens was first sus- 
pected by myself in 1866, when I observed in California a 
pool of crude petroleum filled with maggots. Early in 1867 

*Heus1er, Zeitsch. f. Angew. Chem. 1895. p. 285. Engler, Chem. Ztg., 1896, 
p 197 Kieszling, Ditto, 1896, p 199. Ohlmuller, Arb. aus dem Kaiserl. Ges- 
Amt, Berlin, 1899, XV, p. 366. Friedlaender. Chem. Ind., 1899, p. 343. Holde. 
Lunge, Chem. Techn. Untersuchungs- methoden, III, p. 34. 



ULTIMATE ANALYSIS OF SOLID BITUMENS. 125 

I determined by the soda-lime process the percentage of ni- 
trogen in California bitumens and found an unexpectedly 
large amount in those samples that had been least subjected 
to influences that might produce changes in them. 

When in California in 1894* I showed that nitrogenous 
basic oils existed in all of the semisolid and solid bitumens 
occurring in southern California that were examined by me 
and from widely separated localities. Since then, Mabery 
and others have discovered and determined nitrogen in many 
forms of bitumen from different parts of the world. 

In a paper published in the Jour. Soc. Chem. Ind., June 
30, 1900, Dr. C. F. Mabery says : 

"Nitrogen may de detected in almost any petroleum, but 
usually in minute quantities. 

"The amount found by Beilby in Pennsylvania petro- 
leums was 0.08 per cent, and in Russian oil 0.05 per cent. 
Since we have found it impossible to determine nitrogen by 
any other method than by combustion, measuring the volume 
of nitrogen, I am unable to see how those minute quantities 
were determined. The Kjeldahl method evolves only a part 
of the nitrogen as ammonia, since permanganate evolves only 
a part of the nitrogen as ammonia and a part as nitrogen. 

"Japanese petroleum from some fields contains almost as 
much nitrogen as California oil. 

"A large proportion of nitrogen in California oil was 
early recognized by Peckham, who stated that the proportion 
varied between 0.56 and i.io per cent. In 1892 Salathe found 
proportions of nitrogen varying between 0.75 and 3.5 per 
cent. 

"To ascertain the proportion of nitrogen in California 
oils a number of specimens of crude oil, kindly furnished 
direct from the wells by Mr. Clifford Richardson, were burned 
in a combustion tube and the nitrogen measured. Also in the 
same specimens nitrogen was determined by the Kjeldahl 
method. 

Sixteen specimens were examined. The first four are 
given as an illustration, in Table II. 

Am. Jour. Science, Sept., 1894. 



126 SOLID BITUMENS. 

Source.. Xitrogen by Kjddahl. Nitrogen by volume. 

Summerland oil 0.88 per cent 2.10 per cent 

Los Angeles Field, Eastern 

District 0.47 per cent 1.42 per cent 

Torrey Canon, Venture Co... O.G4 per cent 1.91 per cent 

Wild Bull Gulch, Venture Co. 0.71 per cent 2.39 per cent 

Dr. Mabery continues : 

"In the Kjeldahl determinations the oil was heated until 
the solution became light yellow with complete oxidation of 
the crude oil. 

"These large percentages of nitrogen show that the ni- 
trogen compounds constitute a considerable portion of the 
crude oil. * * * Assuming that the average molecular 
weight of the bases is represented by the formula C 10 H 13 X, 
which is probably too low, the percentage of nitrogen should 
be multiplied by 10, which would give between 10 and 20 per 
cent of the nitrogen bases in the crude oil. 

"The bases which formed the basis of this examination 
were separated from California distillates by Peckham and 
Salathe, by washing a large quantity of the distillates with 
dilute sulphuric acid, and precipitating the base with alkali. 
Portions of these basic oils were kindly placed at my dis- 
posal by Professor Peckham." 

The oils examined by Dr. Mabery were obtained in the 
refinery of the Union Oil Co. of California in 1894, by wash- 
ing 100 barrels of a distillate from crude oil, technically 
known as "40 distillate," with 100 pounds of oil of vitriol 
diluted with nine times its volume of water. This acid solu- 
tion was saturated, and tasted bitter and not sour. A second 
treatment with the same amount of acid and water obtained 
a solution only partially saturated. The saturated solution 
was neutralized with a solution of sodium hydrate and the 
separated precipitate of basic hydrates was dissolved in a 
petroleum distillate nearly as volatile as gasoline. It was 
supposed that the naphtha could be separated from the bases 
by steam as the naphtha had been distilled from a less vol- 
atile distillate by steam. The first distillate by steam came 
over colorless but it was contaminated with the basic oils 
and possessed their familiar odor. Only one-half the naphtha 
used could be distilled by steam. On applying direct heat, 
the naphtha in the distillate decreased until finally the basic 



ULTIMATE ANALYSIS OF SOLID BITUMENS. 127 

oils came over pure, at first of a brown color, then transpar- 
ent and of a cherry red color, and lastly greenish brown, and 
heavier than water, through which the drops sank like shot. 
I he distillation was continued until nothing came over at 
a temperature near the red heat. A dry residue, resembling 
coke, remained in the still, a part of which was soluble in 
hydrochloric acid, from which solution sodium hydrate pre- 
cipitated cream colored flakes. The red and brown oils were 
readily dissolved from solution, as also in a pure state, by 
hydrochloric acid. Dr. Mabery was furnished with a mix- 
ture of these oily distillates and a dilute sulphuric acid solu- 
tion of the whole series from the lighest to the heaviest. 

An examination, in less detail, was made of all the forms 
of bitumen occurring in the region south of the line which 
forms the northern boundary of San Luis Obispo, Kern and 
San Bernardino Counties; with a result that every form of 
natural bitumen and their distillates, whether fluid, semifluid 
or solid, -yielded qualitative tests that indicated the presence 
of compounds, soluble in dilute acids and possessing the pecu- 
liar odor of these basic oils. The petroleums and malthas of 
the Santa Clara valley, Ventura Co., the asphaltums formed 
on the surface by their decomposition from natural causes, 
and the asphaltums from veins near Santa Barbara and at As- 
phalto, in Kern Co., all gave the same reaction.* 

The method which I have employed: for testing solid 
bitumens for nitrogenous basic oils is as follows: Ordinary 
kerosene is washed with concentrated sulphuric acid, decanted 
from the acid and then washed with dilute sulphuric acid, 
then with ammonium hydrate and dried by agitation with 
plaster of Paris. The oil when purified in this way is beau- 
tifully transparent and colorless and is perfectly inert to the 
action of dilute sulphuric acid. 

The semifluid maltha or asphaltum in powder is thor- 
oughly agitated with about ten times its bulk of the purified 
kerosene and after solution is effected an equal bulk of dilute 
(1-9) sulphuric acid is added and the whole thoroughly shak- 
en. The operation can best be conducted in a graduated 

*Am. Jour. Science, Jan., 1894; Ibid, Sept., 1894; Jour. Franklin Insti- 
tute, Nov., 1895; Proc. Am. Philos. Soc., Vol. xxxvi, 103, 1897; Jour. Chem. 
Ind., Vol. xix, June, 1900. 



128 SOLID BITUMENS. 

stoppered cylinder, of about 25 c. cm. capacity. After several 
shakings, the mixed liquids are allowed to rest, when the 
kerosene solution will float above the dilute acid. A con- 
venient portion of the acid solution is then removed with a 
pipette and introduced into a second jar, where it is neutral- 
ized with a solution of sodium hydrate. If any considerable 
amount of these compounds are present they will float on the 
surface of the liquid; smaller amounts will give their pecu- 
liar odor. 

Oxygen is estimated by difference. This is a very un- 
certain and unsatisfactory procedure. It approximates accu- 
racy only when all of the other constituent elements have 
been carefully determined, as it is obvious that all the losses 
and errors accumulate in the residual difference between the 
sum of the percentages of known elements and one hundred 
per cent. 



CHAPTER XI. 
THE PROXIMATE ANALYSIS OF SOLID BITUMENS. 

As is the case with all other methods of chemical inves- 
tigation, the investigation of bitumens, as at present con- 
ducted, represents a growth. The starting point is the 
classical research of Bous.singault, first described in 1837.* 

It must be remembered that this research was under- 
taken more than seventy years ago, when organic chemistry 
was in its infancy as compared with to-day, and when the 
methods of investigation with which the chemists of to-day 
are familiar were unknown. It detracts nothing from the 
value of Boussingault r s work to say that it is worthless as 
a guide in modern research. 

I have found by years of experience that solid bitumens 
cannot be investigated by ordinary methods of distillation. 
They are decomposed at temperatures much below that at 
which any portion of them becomes volatile. I have distilled 
them in California and elsewhere under the most diversified 
conditions with one uniform result. Under atmospheric 
pressure, with any of the various forms of retort that I have 
used, only products of destructive distillation can be obtained. 
These products vary in character with the crude material. 
Trinidad pitch, either lake or land, is decomposed when 
heated to a temperature of 100 C. with a copious evolution 
of hydrogen sulphide. Whether or not this reaction would 
attend distillation in vacuo I do not know. 

When I first made a laboratory examination of California 
bitumens, which were both fluid, semifluid and solid, I con- 
trived an apparatus which to answer my purpose had to fulfill 
the following conditions. It should be capable of working 
not more than one and one-half liters, and admit of being 
heated by an ordinary gas furnace. The joints should sus- 
tain a pressure of 40 Ibs. per sq. in., and it should be so con- 
structed as to admit of the ready extraction of the coke. I 

*(Ann. de Chem. et de Phys. (2), LXIV, 141, p. 91.) 

I2 9 



130 SOLID BITUMENS. 

could find no description of any such apparatus, but after 
numerous failures and corrections I found my want so well 
and fully supplied, that I am led to offer a description, for 
the benefit of those who, like myself, have felt the need of 
such an instrument. 

Upon each extremity of a piece of wrought iron gas- 
pipe, 3 ins. in diameter and 20 ins. in length, a c^p is securely 
screwed. The caps should be heated nearly to redness and 
screwed on to the cold pipe in order that by their contraction 
they may be more firmly secured. The pipe is then put in a 
lathe and the caps turned off in such a manner as to leave 
a band upon each end of the pipe, about % in. -in width, and 
two circular discs of iron, each about 4 in. in diameter, and 
*4 in. in thickness, having a projection upon one of their sur- 
faces to which a wrench may be applied. The edges of each 
extremity of the pipe with the bands are now carefully turned 
off, presenting smooth surfaces slightly beveled inwardly. 
The plane surface of each of the discs is then so turned off 
upon its circumference, that it will exactly fit the beveled 
edge of the pipe. This completes the retort. 

A stout parallelogram is then made half an inch longer 
and wider than the retort, one of the shorter sides of which 
should contain in the middle a stout set-screw, and the other 
an orifice made to fit the projection upon the disc. This may 
be called the frame. 

Two holes are then drilled a short distance from either 
extremity of the retort, in a line parallel to the axis of 
the retort, and plugs fitted to them. One of these should 
admit a ^-in. and the other a i-in. gas-pipe. With 
this arrangement the retort may be used either for 
pressure distillation with a valve, or for distillation by the 
ordinary process. It also admits of being connected with an 
apparatus for furnishing superheated steam or carbonic acid 
gas, either of which are sometimes used to assist the distilla- 
tion of hydrocarbons. Both the goose-neck and valve should 
be connected with the retort by a short piece of gas-pipe and 
a brass "union" or coupling, as the difference in the expan- 
sion of brass and iron would cause a joint of the two metals 
to leak very badly when subjected to a high temperature 
The goose-neck may be made of the ordinary form, tapering 



PROXIMATE ANALYSIS Ol- SOLID BITUMENS. 131 

from i in. to l /^ in., and about 10 ins. in length. The material 
should be copper, brazed. 

In order to use the retort the plugs are inserted, 
one of the discs is luted with a very thin paste 
of plaster of Paris and firmly pressed into its seat. 
The retort is then slipped into the frame and left a 
moment for the luting to set, the open end being uppermost. 
The oil is next poured in and the other disc luted into its 
seat, the frame adjusted and the set-screw firmly set up, so 
as to securely fasten both discs in their places. The goose- 
neck or valve is then adjusted, and the connections made with 
the worm and receiver. It will be observed that all the ex- 
pansion that takes place in this retort brings the different 
portions of the apparatus more firmly together, instead of 
causing them to crack. apart and leak with every slight varia- 
tion of temperature, as is usually the case. With this ar- 
rangement I was able to 'distill 1500 c. cm. of petroleum to 
dryness, the last portions coming over at a red heat. The dis- 
tillation was commenced with two ordinary Bunsen gas 
lamps, increased as required to four, and toward the end of 
the operation to six the latter number being sufficient to 
bring the side of the retort in contact with the flame to a 
bright cherry-red heat.* 

The apparatus is equally convenient for distilling small 
quantities of semifluid and solid bitumens; but while such 
examinations by distillation are sometimes desirable they are 
at present not to be considered in any sense analytic. The 
most elaborate, as well as the most successful research upon 
solid bitumens in which this method was employed was de- 
scribed by Mr. Clifford Richardson in The Jour. Soc. Chem. 
Ind., Jan. 31, 1898. 

The methods of analysis by solution remain. Solution 
may certainly be properly considered a chemical reaction, and 
the more solvents that can be applied to a solid with clearly- 
defined results that can be repeated with accuracy, the more 
complete must be the method of analysis. To dissolve a bitu- 
men in carbon disulphide, which is a universal solvent for 
bitumens, does not analyze the bitumen, although it may sep- 
arate the bitumen from its impurities ; but to subject a bitu- 

*Am. Jour. Science (2), xliv, 230; Chem. News, xvi, 199. 



132 



SOLID BITUMENS. 



men to the action of several solvents in succession, by which 
the bitumen can be referred to a distinct class, is a valuable 
analytical process. 

These considerations have been impressed upon my mind 
during the several years last past, in which I have been at- 
tempting to arrange a process of analysis that shall apply to 
all bitumens, and enable the analyst to distinguish, both 
alone and in mixtures, the several, varieties of bitumen, in a 
manner similar to the schemes that have been proposed for 
alkaloids or other organic compounds. 

The subject is still under discussion and much remains to 
be done in perfecting details which must be frequently modi- 
fied to suit special materials and special conditions. Parian- 
ite or Trinidad pitch is about as complex as any bituminous 
material submitted to analysis and it is selected for a de- 
tailed description of analysis by solvents for the purpose of 
showing not only what has been accomplished but what re- 
mains to be accomplished in this particular form of research. 

Parianite may be regarded either as an emulsion of gas, 
mineral water; bitumen, that is, compounds of carbon, hy- 
drogen and nitrogen, oxygen and sulphur, any or all of the 
last three, with organic matter not bitumen, and mineral mat- 
ter consisting of silica and clay as impurities ; or, it may 
be regarded as an emulsion of gas, water holding mineral 
salts in solution, bitumen as above described, with complex 
organic salts of iron, alumina, lime and magnesia, with ulmic 
and perhaps other acids, with amides and amines, with ferrous 
sulphide, and silica, some portions of which are in combination 
with the other ingredients and the remainder free. Either alter- 
native exhibits a very complex substance, but each quite unlike 
the other. By what means can it be determined of what the 
mixture really consists? Certainly not by any process that 
separates a hypothetical substance called petrolene and a sec- 
ond called asphaltene, a third called organic matter not bitu- 
men, and a fourth called mineral matter. One might just as 
well analyze a log of wood by burning it into smoke, flame 
and ashes. 

THE GAS. 

We will begin at the lake with the gas. I visited the lake 
on Point La Brea on four different days, and practically 



PROXIMATE ANALYSIS OF SOLID BITUMENS. 



133 



walked all over the deposit, both inside and outside the lake. 
I did not once recognize the odor of hydrogen sulphide. 
When I was in California in 1865, it was stated that the big 
spring on the upper Ojai plateau discharged carburetted hy- 
drogen. I found the gas would not burn, and then I gathered 
some of it and found it was nearly pure carbon dioxide. I 
suspect that the greater part of the gas discharged from 
the lake is also carbon dioxide. It is the normal product of 
the deoxidation of the sulphates contained in the lake water, 
as sulphuric oxide yields more oxygen than is sufficient to 
convert the bases present into carbonates. No doubt the 
deoxidation of the sulphates in the water is attended with a 
variety of reactions resulting in a variety .of chemical prod- 
ucts, of which both carbon dioxide and hydrogen sulphide 
form a part. The proper place to investigate these gases is 
at the lake. THE LAKE WATER. 

Mr. Richardson has fully investigated the lake water, 
and in his report in 1892 he gives his results in great detail. 
The water used by him was taken from the water floating 
on a kettle of melted pitch that was being refined. It was 
probably more highly concentrated than lake water, and had, 
perhaps, lost some of its volatile ingredients. He gives the 
following analytical results: 

IN ONE KILOGRAM. Grams. 

Cl 6.7757 

SO, 5.5409 

SO- 0467 

S 2 O T trace 

H 2 S trace 

S trace 

SiO a 0688 

B 2 O 0117 

I 0008 

Br trace 

PzOs none 

Na 6.5149 

NH 4 4071 

K 3391 

Li 0271 

Ca 5280 

Mg 2666 

Fe 0720 

Al trace 

Mn none 

Cs & Rb none 

Organic 4901 

Oxygen none 

21.0896 



134 



SOLID BITUMENS. 



It is probable that these results indicate but do not rep- 
resent the composition of lake water. They also indicate the 
composition of the water saturating the pitch. This water, 
examined by Mr. Richardson, has an acid reaction. 

In a paper published by Mr. Richardson (Jour. Soc. of 
Chem. Industry, January, 1898), he gives an analysis of 
water from a spring that arose in the pitch : 

IN ONE KILOGRAM. 

Grams. 

Specific gravity 1.0599 

Solids at 110 C 82.100 

Sodium, Na 27.193 

Potassium, K 0.528 

Chlorine, Cl '. 38.210 

Sulphuric acid, SO 3 3.2<7 

Calcium oxide, CaO trace- 
Magnesium oxide 0.500 

Carbonic acid, CO 2 3.700 

Silica, SiO 2 0.222 

Organic matter ? 



73.56G 

From these analyses it appears that the lake water is 
rich in chlorides and sulphates of sodium and iron, with 
iodides, bromides and borates, in the first instance, and car- 
bonates in the second. 

AQUEOUS SOLUTION OF THE PITCH. 

One hundred grams of a fine specimen of commercial 
lake pitch were digested with successive portions of distilled 
water at a temperature of 60 to 70 C., until there was no 
longer a reaction for either Cl or SO 3 . The first portion con- 
tained a large amount of ferrous sulphate. The solution, on 
standing, deposited a small amount of ferric oxide. The solu- 
tions were concentrated to I liter and portions of 100 c. cm. 
were evaporated over a water bath. The residue contained 
chloride and sulphate of iron and sodium. Probably a larger 
portion would give reactions for all the soluble salts obtained 
by Mr. Richardson from lake water. This residue also con- 
tained a small amount of organic matter that was not deter- 
mined. The percentage of this residue was 1.135 P er cent, 
of the pitch. 



I'ROXtMATli ANALYSIS Ol< SOLID BITL'Ml-\.>. 135 

THE ALKALINE SOLUTION. 

It is impossible to visit the pitch lake without observing 
that an immense amount of partially decayed vegetation is 
entombed in the pitch. Enormous stumps are uncovered, 
with trunks and branches of trees in every stage of decay, 
from solid wood to large masses of humus that a kick will 
scatter, precisely as if they were found in the peat of a bog. 
This humus becomes kneaded and incorporated with the pitch 
precisely as is the mineral matter, and, what has not been 
properly recognized, the humus on a colossal scale has 
formed those peculiar compounds, the precise natures of 
which are but little known, but which Mulder, Boussingault 
and others have referred to amides and double salts, in which 
ammonia, the peat acids and iron, and especially alumina, 
are combined into exceedingly complex compounds, insoluble 
in water, but readily yielding to solutions of alkaline hy- 
drates and carbonates. These reactions are brought together 
from many researches and admirably treated by Prof. S. W. 
Johnson in his "How Crops Feed," pp. 276-280, to which the 
reader is referred. The treatment there recommended to be 
applied to soils for the determination of the humus com- 
pounds has been applied to this sample of Trinidad pitch with 
the most satisfactory results, and a flood of light is thrown 
upon the problems presented by these unique and complex 
substances. 4.9325 gms. of the dried residue which 
represent 5,000 gms. of air-dried pitch, were digested 
in successive portions of a solution of dry sodium carbonate, 
5.3 gms. to I liter of distilled water. The first portion was 
colored as dark as port wine and the last portion was uncol- 
ored. The alkaline solution was acidulated with hydrochloric 
acid and the precipitated ulmic acid was collected on a bal- 
anced filter, dried at 100 C. and weighed. The ulmic acid rep- 
resented 1.542 per cent of the pitch. The residue from the 
sodium carbonate solution was then boiled with a dilute solu- 
tion of sodium hydrate and the dissolved ulmin was precipi- 
tated with hydrochloric acid in considerable amount. 

The acid solutions were neutralized with sodium hydrate, 
acidulated with acetic acid and the aprocrenic acid precipi- 
tated with acetate of copper. Only a trace of crenic acid was 



136 SOLID BITUMENS. 

precipitated by ammonia. This might reasonably be ex- 
pected, as crenic acid is being continually converted to apo- 
crenic acid by contact with reducing substances, of which bitu- 
men is a notable instance. I am inclined to think that Prof. 
S. W. Johnson's observation, that ulmin represents only the 
ulmic acid of difficulty decomposable ulmates, is correct 
("How Crops Feed," p. 225, note). It is well known that 
ulmic acid and ulmin have the same composition, but the first 
is readily soluble in Na 2 CO 3 , while the latter requires pro- 
longed boiling with NaOH for its solution. I believe that the 
ulmin represents only the ulmic acid that is in combination 
with alumina and iron, which compounds are decomposed with 
considerable difficulty. 

Wiley, in his "Principles and Practice of Agricultural An- 
alysis," Vol. I, p. 28, recommends for the determination of 
humic and ulmic acids the use of the Huston-Grandeau 
method, as follows : 10 gms. of the soil are washed with a 3 
per cent solution of HC1, and then washed into a 500 c. cm 
cylinder with a 4 per cent solution of ammonium hydrate. 
Shake and let remain in a horizontal position for 36 hours. 
Determine the humus in an aliquot part. This is, no doubt, 
a very good method for ordinary soils containing free peat 
acids and their salts of lime and magnesia; but, used on No. 
8, the amount of ulmic acid obtained was only 0.044 per cent 
against 1.542 per cent obtained by the sodium carbonate 
method. In Parianite the peat acids are, no doubt, combined 
with iron and alumina, as only traces of lime and magnesia 
were found in the HC1 solution. 

The ammonia that has been observed escaping from 
kettles of melted pitch when it is refined is, without doubt, 
derived from the amido compounds referred to above. The 
relation which the pitch bears to a soil is strikingly shown 
in the luxuriant vegetation that covers the pitch wherever it 
is not in motion. Outside the lake a tropical jungle grows, 
with its roots penetrating the pitch and forming a sod of great 
tenacity, which often renders tons of the pitch worthless from 
admixture of vegetable matter. Such pitch is universally 
rejected. 



PROXIMATE ANALYSIS OF SOLID BITUMENS. 137 

THE DETERMINATION OF WATER. 

The pitch is taken from the lake dripping wet. It begins 
to dry out immediately, but it requires a long time to com- 
pletely remove the water if the lumps are unbroken. It is, 
however, easily dried if pulverized and placed in the sun. By 
thus drying to a constant weight the water may be deter- 
mined. 

Another method that I have found very convenient for 
determining water in semifluid or solid bitumens is to dissolve 
the bitumen in refined and recently purified (see page 190) 
illuminating oil and distil in an alembic or tubulated flask, 
collecting the distillate in a graduated cylinder and measur- 
ing the water, which may be estimated to weigh a gm. 
to ic. cm. at 60 F. For this purpose, at least 50 gms. of the 
bitumen should be dissolved in 200 c. cm. of the liquid, and 
the distillation should be continued until no more water passes 
over. 

PETROLEUM ETHER SOLUTION. 

For this determination three washed filters should be bal- 
anced. In two of them should be weighed I gm. of the pitch. 
These filters should be placed in separatory funnels and ex- 
hausted with dry petroleum ether, of 74 B. or higher, as rap- 
idly as possible. It is rare to find petroleum ether on the 
market, free from water; it should always be agitated with 
dry plaster of Paris before being used. The percentage of 
dry pitch dissolved by the petroleum ether will vary within 
narrow limits from 32 to 36 per cent. 

If the petroleum ether solution be allowed to stand, it 
deposits a film upon the surface of the containing vessel 
beneath the liquid. This deposit is not a precipitate. If the 
vessel is of glass, the entire surface of the glass beneath the 
liquid is covered with the film, from which the liquid may be 
cleanly poured. This film readily dissolves in chloroform to 
a transparent solution. This chloroform solution evaporated 
to dryness over a water-bath gave 1.884 P er cent of the pitch, 
of a brilliant black solid, which, when heated, melted, distilled, 
intumesced and burned to a very porous light ash that ap- 
peared to be alumina. The ash amounted to 41.508 per cent 
of the solid mass or 0.0782 per cent of the pitch. 



138 SOLID BITL'MEXS. 

if the petroleum ether soluble be treated in solution with 
fuming nitric acid, an orange-colored nitro derivative is ob- 
tained, from which the petroleum ether may be easily distilled. 
An examination of these nitro derivatives is a much more 
promising field for research than the products of distillation, 
contaminated as they are with the inevitable decomposition 
products of high temperatures. 

THE TURPENTINE SOLUTION. 

When in California, in 1894, I treated 100 gms. of lake 
pitch with boiling spirits of turpentine, and upon adding to 
the solution a large excess of petroleum ether, obtained a 
copious brown precipitate. I gathered this precipitate on a 
filter and washed it with petroleum ether, in which it is wholly 
insoluble. It is also insoluble in ethyl ether and ethyl and 
methyl alcohol. Heated in a platinum crucible, it yields a 
large percentage of ash. This ash consisted of: 

Silica 

Alumina 

Iron 

For a long time I supposed this precipitate was asphaltene, 
but on attempting -to determine the sulphur in it I found it 
was an organic compound of silica and alumina. I have not 
yet completed my investigation of this material, which I be- 
lieve is a double salt of alumina, containing ulmic acid. 

More than 12 per cent of the precipitate may be dis- 
solved in solution of sodium carbonate and a still larger per- 
centage may be dissolved in a solution of sodium hydrate, 
from both of which solutions hydrochloric acid will precipitate 
an organic acid. This material also furnishes a much more 
inviting field for .research than the decomposition products 
of distillation. 

THE CHLOROFORM SOLUBLE. 

When the residue left on the filter from treatment with 
boiling spirits of turpentine is treated with cold chloroform, 
a third portion is dissolved. The percentage varies with the 
pitch. In those analyzed by Miss Linton it varied in the five 
land pitches from 3.139 to 8.185, in the lake pitches from 2.137 
to 7.222, and in those from the annular space from 4.800 to 
6.900. 



PROXIMATE ANALYSIS OF SOLID BITUMENS. 139 

When the soluble is evaporated from the chloroform it 
forms a brilliant, black, hard varnish. Heated, the varnish 
melts, intumesces, gives off heavy vapors which burn with a 
smoky flame, leaving a red ash, consisting chiefly, if not 
wholly, of ferric oxide. In one instance a portion of this 
varnish yielded 0.779 P er cent f tms ferruginous ash. 

This soluble is precipitated from its solution in benzole 
or chloroform upon the addition of an excess of petroleum 
ether, as a seal-brown powder. This precipitate may be 
washed with petroleum ether, ethyl alcohol or ether, in all of 
which it is insoluble. Analyses, that have been fully described 
elsewhere, and for which no claim for absolute accuracy is 
made, have shown this precipitate to consist of an organic 
sulphosalt of iron (Jour. Soc. Chem. Ind., December, 1897, 
Xo. 12, Vol. XVI). Here is also a more profitable field for 
research than is found among the decomposition products of 
distillation. 

THE HYDROCHLORIC ACID SOLUTION. 

Whenever limestone forms any part of a bituminous mix- 
ture, whether natural or artificial, it is essential that it should 
be determined. When crushed stone is used, some portion of 
it is usually soluble in hydrochloric acid. Gypsum is also dis- 
solved by it, and may be detected by testing the solution for 
sulphuric acid. A very small percentage of the residue of 
Parianite remaining after solution in chloroform is soluble in a 
10 per cent solution of hydrochloric acid. I have not ascer- 
tained what elements enter this solution. 

THE RESIDUE. 

That which remains on the filter after treatment with 
hydrochloric acid consists of cellulose and humus, mixed with 
such mineral matter as is not in organic combination in the 
pitch. The organic matter cannot be burned off without de- 
composing pyrite and burning out more or less of the sulphur, 
as the ash of the filter is usually saturated with ferric oxide 
in the form of colcotha. The proper procedure is to cut the 
filter in small pieces, mix these pieces with sodium carbonate 
and potassium nitrate and deflagrate. The silica, iron and 
alumina can then be determined while the sulphur appears 
as sulphuric acid, in the usual way. By determining the sul- 



140 SOLID BITUMENS. 

phur in another portion of the pitch in like manner and deduct- 
ing the sulphur found in the residue from the whole amount 
of sulphur, the sulphur in organic combination can be ascer- 
tained. At the same time that this total amount of sulphur 
is determined, the total amounts of silica, alumina and iron 
can also be correctly determined. This correct total amount 
of mineral matter will be found to be considerably in excess of 
the amount found by the usual method of analysis by solvents ; 
inasmuch as an appreciable amount of alumina and iron in 
combination with organic radicals pass into solution, which 
exist in the pitch dissolved in the bitumen, and which in the 
process of analysis pass into the solutions formed by the 
various solvents employed. 

THE ORGANIC MATTER NOT BITUMEN. 

Precisely of what this consists has not been determined. 
It is obtained by burning the residue that remains from the 
solution in chloroform, at a dull red heat. If the pitch is not 
finely pulverized, but is treated in coarse lumps, the residue 
from the chloroform contains fragments of vegetation of ap- 
preciable size. There is also a considerable amount of an ex- 
ceedingly fine gray powder that i's easily recognized as ferrous 
sulphide. A determination of the sulphur in this residue gave 
0.8844 P er cent f the pitch; this is equivalent to 9793 per 
cent of the resdue, or, 18.368 per cent of the residue of fer- 
rous sulphide. These figures are suggestive rather than final. 

In the ordinary method of analysis by solvents, with com- 
bustion of "organic matter not bitumen" and determination 
of the residue from the combustion, the organic matter not 
bitumen amounted to 8.507 per cent and the mineral matter to 
32.243 per cent. How large a part of the organic matter not 
bitumen was sulphur cannot be conjectured; but no question 
can be entertained for a moment that a very considerable por- 
tion of the 3.639 per cent of sulphur is. lost in that way. 
Whatever the amount may be, the total per cent of material 
that is not bitumen, obtained by solution, is 4O-75> while the 
sulphur, silica, alumina and iron, by the direct method amounts 
to 43.989 per cent. 



PROXIMATE ANALYSIS OF SOLID BITUMENS. 141 

THE MINERAL MATTER. 

This is the residue left in the crucible after the organic 
matter not bitumen has been burned off. It consists of grains 
of silica with a small amount of alumina and a much larger 
proportion of ferric oxide in the form of colcotha, which in- 
dicates that it is a product of decomposition, and that, too, of 
a substance that is very intimately mingled with the entire 
mass of the residue and even the fiber of the paper. The paper 
is as completely filled with anhydrous ferric oxide as if it had 
been previously soaked in a saturated solution of ferrous sul- 
phate. 

The average totals of this mineral matter in the seven- 
teen specimens of normal crude pitch is 36.444 per cent. If, 
however, the mineral matter, that is, the silica, alumina and 
sulphur, are directly determined, they will amount to: 

Per Cent. 

Silica 19.593 

Iron and alumina 20.272 

Sulphur 3.505 



Total 43.370 

By solution 36.444 



Difference 6.926 

This difference of nearly 7 per cent is certainly repre- 
sented by constituents of the pitch, a part of which pass into 
solution in the solvents of the pitch and a part of which are 
volatilized as "organic matter not bitumen."* 

Following the reading of this paper before the Franklin 
Institute of Philadelphia, of which the above description 
forms a part, were several very pertinent criticisms, from 
which I quote: 

Dr. S. P. Sadtler stated that he was ready to admit the 
complexity of constitution of Parianite or Trinidad pitch as 
maintained by Professor Peckham, in that it probably con- 
tained some of the mineral bases in an organic combination 
whether we concede that the organic substance is really 
humic acid or not ; that it was moreover, so unstable that it 
could not be heated directly without some decomposition. 



*Jour. Franklin Institute, March, 1900. 



1 42 SOLID BITUMENS. 

However, he did not think that this complexity applied to all 
natural bitumens he recalled the natural bitumen of Uvalde 
Co., Texas, which could be extracted from the limestone rock, 
in which it occurred naturally, by the use of a naphtha sol- 
vent ; that the same was true of the natural bitumen of Santa 
Barbara Co., Cal., where the Sisquoc asphalt was extracted 
in that way ; that he had analyzed a natural bitumen from 
Joplin, Mo., occurring in the cavities in the zinc-bearing rocks, 
which was also almost entirely soluble without residue in pe- 
troleum naphtha. With reference to Dr. Peckham's method 
of analysis of bitumens, he was not satisfied that turpentine 
was to be depended upon as a desirable solvent. It was ob- 
vious that freshly-rectified spirits of turpentine, and that 
which had been exposed to the air for a time as warm turpen- 
tine upon a filter and had in consequence become somewhat 
resinous, would have distinctly different solvent powers. He 
had had occasion, in connection with another matter, to test 
this difference between turpentine free from resin and turpen- 
tine carrying resinified products, and knew that it affected the 
solvent action notably. To use turpentine, therefore, one would 
have to note its optical constant so as to insure its entire uni- 
formity. 

Dr. Sadtler stated that he had at one time proposed ace- 
tone as a solvent in asphalt analyses in place of petroleum 
ether, because it could be had of fixed boiling point and per- 
fect purity, but found that its solvent power varied from that 
of petroleum naphtha, and therefore no longer tried to use it 
as a substitute. What is wanted is a study of the action of 
a series of solvents of .fixed purity upon different natural bitu- 
mens. 

Dr. Wm. C. Day gave some results of determinations of 
nitrogen in Utah Gilsonite by the Kjeldahl method ; upon 
which Dr. H. F. Keller remarked that more concordant results 
and certainly more reliable figures might be obtained by com- 
bustion of the material with copper oxide than is possible with 
the Kjeldahl method. 

Mr. Alfred H. Allen, Sheffield, England (correspondence) 
remarked, I am rather struck by the absence of any elemen- 
tary analyses of the products obtained. 

To all of which the author replied : 



PROXIMATE AXALYS1S Ol : SOLID B1TUM1LXS. 143 

The use of spirits of turpentine was first suggested by 
the directions given in the first edition of Allen's "Commer- 
cial Organic Analysis." It is directed there that the bitumen 
in European asphaltic rock be dissolved from the mineral 
matter in freshly distilled Russian turpentine. The turpentine 
should be freshly and doubly distilled. In any case the filter 
should not be digested in turpentine, which, poured upon the 
filter while hot, has been allowed to get cold. The stopcock 
in the funnel should be closed, the filter filled with boiling tur- 
pentine, the stopcock immediately opened and the hot turpen- 
tine allowed to run off as rapidly as possible. This should be 
repeated until the turpentine is discharged colorless. There 
are very great differences observed in the action of boiling 
turpentine upon asphaltums and bituminous minerals from 
different localities. In some cases the solution is as readily 
affected as sugar and water; in other cases the solution takes 
place much more slowly. The points made by Dr. Endemann 
and Sadtler are theoretical, not practical ; any other sol- 
vent, as, for instance, any of the benzole series that will dis- 
solve the material not soluble in petroleum ether, will yield 
this precipitate on dilution with a large 1 excess of petroleum 
ether. I have digested this precipitate in dilute hydrochloric 
acid, then in a dilute solution of sodium hydrate, which be- 
came highly colored, and then obtained a copious precipitate 
of an organic acid, in brown flocks, when trTe sodium hydrate 
solution was acidulated. 

It is true that on a large scale, the bitumen of the Uvalde 
County bituminous limestone has been extracted with petro- 
leum naphtha, yet I have never found among the many sam- 
ples of this rock that I have tested a single sample in which 
the bitumen was all soluble in petroleum ether. It is, howevei. 
practically, all soluble in boiling turpentine. On a large scale, 
the portion insoluble in petroleum ether is washed out of the 
rock by the solution of the remainder in the petroleum 
naphtha, and the purified bitumen consists of a mixture of the 
two solubles. 

I have for some time been of the same opinion, so well 
expressed by Dr. Sadtler, that "What is wanted is a study of 
the action of a series of solvents of fixed purity, etc." I have 



144 SOLID BITUMENS. 

in hand the material for precisely this work, but have hitherto 
been unable to devote to it the necessary time. 

I also recognize the force of Mr. Allen's remark concern- 
ing the absence of elementary analyses. The reason is that 
hitherto I have not been able to obtain the substances de- 
scribed in this paper under such conditions and in such quan- 
tity as to make ultimate analyses advisable. Ultimate analysis 
should follow the study of the action of solvents of fixed 
purity. I have for some time been studying the action of pure 
alcohols, both absolute and of definite dilution, as well as 
aceton, ethyl ether and chloroform separately and in series. 
There is work enough on these problems to fill the twentieth 
century. 

In further illustration of the value of this method when 
applied to the practical examination of bitumens, we give be- 
low the results of an examination of Turrellite the bitumin- 
ous coquina found in Uvalde Co., Texas. 

The mineral itself is a gray mass, apparently of shells, 
cemented together with bitumen. It is exceedingly tough and 
difficult to break a property that is easily accounted for when 
the material is deprived of its bitumen by being digested in 
chloroform. The mineral residue is then discovered to be a 
coquina or shell limestone possessing considerable stability 
without the bitumen. The shells are cemented together, and 
the cavities of many of them contain rhombspar and fragments 
of other shells, showing that the shell rock had been formed 
before the bitumen was projected into it. 

Analyzed by solvents, there were obtained the following 
results : 

Per Cent. 

Soluble in petroleum ether 9.415 

Soluble in spirits of turpentine, after 4.121 

Soluble in chloroform, after Trace 

Soluble in dilute hydrochloric acid, after 84.894 

Sulphur in residue 0.138 

Silica and clay 1.432 



100.000 



The average total bitumen is 13.536 per cent., of which 
the ^petroleum ether soluble is 69.555 P er cent > and tne spirits 



PROXIMATE ANALYSIS OF SOLID BITUMENS. 145 

of turpentine soluble is 30.445 per cent. This gives a bitumen 
wholly soluble in spirits of turpentine, of which 69.5 per cent 
is soluble in petroleum ether a very high-grade bitumen. 
Five gms. of the rock, analyzed in duplicate, gave an average 
of 1.13 per cent of sulphur in the rock; 1.13 per cent 0.1381 
per cent found in the mineral residue, leaves 0.9919 per cent 
of the rock, of sulphur in the bitumen, or, of the bitumen 7.328 
per cent. 

Digestion for several days in water at 60 70 C., yielded 
a solution containing 0.126 per cent of the rock, which con- 
sisted of a trace of organic matter and calcium carbonate. 
There were no sulphates soluble in water. The portion dis- 
solved by dilute hydrochloric acid consisted of calcium car- 
bonate with traces of magnesium, iron, and sulphuric acid. 
The insoluble residue remaining on the filter consisted of 
silica, clay, and very small grains of pyrites of appreciable 
size. Caustic alkalis were without appreciable action on the 
rock. Fuming nitric acid acted upon it with great energy, 
dissolving the mineral matter and converting the bitumen 
into a brittle, charred mass of carbonaceous matter. The bitu- 
men extracted from this rock, when analyzed by itself, yielded 

Per Cent. 

Petroleum ether 71.28 

Boiling spirits of turpentine, after 28.72 

100.00 

The results are nearly identical with those obtained from 
the rock. The sulphur in the bitumen amounted to 7.582 per 
cent. The bitumen is not acted on by water, strong acids, or 
alkalis. Fuming nitric acid coverts it into a friable, carbon- 
aceous mass. 

The above described work is analytical, as far as it goes. 
It is admittedly very imperfect, but it tells, nevertheless, its 
story concerning the constituents of this bituminous rock. 
There is no reason for believing that there is any oxygen com- 
pound in the bitumen contained in this rock. The bitumen is 
very pure, and contains a very large percentage of sulphur. 
The bitumen contains only a trace of mineral residue when 
burned. 

Following the suggestion of Dr. Sadtler, as to the use of 
solvents "of fixed purity/' I have been engaged for several 



l.io SOLID BJTi'MEXS. 

years in the intervals occurring in the routine work of our 
laboratory in a research from the results of which a series of 
solvents might be selected with which to successively exhaust 
any bitumen that might be made subject to analysis. This 
research work has been repeatedly interrupted and while the 
results obtained have been unsatisfactory from their incom- 
pleteness they have been very satisfactory as far as they have 
gone. 

The solvents selected were 95 per cent methyl alcohol, 
pure acetone, washed ethyl ether and pure chloroform. The 
alcohol was redistilled, the acetone was redistilled over pure, 
dry, sodium carbonate. The ether was used as purchased, 
and the chloroform was washed with concentrated sulphuric 
acid and distilled over pure, dry, sodium carbonate. The sam- 
ple of Trinidad pitch used was brought from the lake by my- 
self in 1895. It was first exhausted with distilled water in a 
large flask. The residue was dried, filled into the capsule of 
a Soxhlet apparatus, with ground glass joints, and exhausted 
with the alcohol. 

It was then exhausted with the acetone. 

It was then exhausted with the ether. 

It was then exhausted with the chloroform. 

The residue was dried. 

The alcohol extract was a soft, brown, solid, possessed of 
great viscosity and without perceptible odor. In solution it 
was light brown in color. 

The acetone extract was a dense liquid that scarcely 
flowed, of a deep cherry red color and forming cherry red 
solutions. Its viscosity resembled old balsam of fir or par- 
tially dried copal varnish. 

The ether extract was a brilliant black, soft solid. 

The chloroform extract was a dull, black, brittle solid. 

The residue was a dull brown, pulverulent solid, resem- 
bling a dry peaty soil. 

This residue gave a copious extract to ammonium hydrate 
that when precipitated with hydrochloric acid gave a brown 
flocculent precipitate, that when dried burned with explosive 
violence. 

The extraction by means of the capsules was a very long, 
tedious, unsatisfactory process. The capsules did not hold 



PROXIMATE ANALYSIS OF SOLID BITUMENS. 147 

the finest particles of mineral matter and no certainty could 
be had that the solvent did not form channels through the 
mass leaving portions of the mass from which the extraction 
was incomplete. This method was defective in another re- 
spect. Boiling acetone dissolved a substance in small quan- 
tity that was deposited on cooling. It was a cream colored, 
brittle solid that has not been investigated. The chloroform 
solution deposited on standing a brown pulverulent solid in 
appreciable amount. This has not been investigated. 

It was therefore determined to make an extraction with- 
out the aid of heat in a separatory funnel. The water extrac- 
tion has been made with results very near those previously 
made. The alcohol extraction has been made with very sat- 
isfactory results. The acetone extract is nearly completed. 
The residue from the acetone extraction, that still retains both 
the ether and chloroform extracts, is a brown pulverulent 
solid without a suggestion of bitumen of any description. 



CHAPTER XII. 

THE TECHNICAL ANALYSIS OF SOLID BITUMENS. 
INTRODUCTION. 

Technical analysis may be applied to natural solid bitu- 
mens including bituminous rocks, to factitious solid bitumens, 
and to mixtures of natural and factitious bitumens; also to 
street surfaces, to street mixtures, to asphalt blocks and any 
other bituminous mixtures. 

All natural solid bitumens contain besides their content 
of bitumen a greater or lesser amount of insoluble material, 
which is partly organic and partly mineral matter, from which 
the bitumens may be separated by solution or extraction. 
Factitious bitumens on the contrary contain little or no in- 
soluble organic or mineral matter. 

While the analysis of the above named classes of sub- 
stances will be each considered separately, the determination 
of the total bitumen in any or all of them will first claim our 
attention. For the determination of this total bitumen a sol- 
vent is selected that will completely separate all of the soluble 
from the insoluble constituents of the substances analyzed, by 
the simplest and most direct operation. 

Bitumen is completely soluble in chloroform, bisulphide 
of carbon, benzole and perhaps other homologues of benzole. 

As a solvent, chloroform is to be preferred, as its odor is 
agreeable and it does not readily ignite ; but bisulphide of car- 
bon, while much more offensive, and very inflammable, is very 
much less expnsive. Either of these liquids is very volatile at 
the ordinary temperature, and may therefore be evaporated 
from the dissolved bitumens without decomposing them or re- 
moval of the most volatile constituents of them. 

While the two solvents mentioned are universal solvents 
for bitumens, there rxre bitumens that are wholly soluble in 
spirits of turpentine but this liquid can only be evaporated 
from the extracted residues with great difficulty; there are 
cases in which its use is to be highly recommended. Acetone 

148 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 



149 



and alcohols also furnish valuable assistance in helping to dis- 
tinguish bitumens from different sources. 

METHODS OF DISTILLATION. 

Reference is here made to the research conducted by Bous- 
singault in 1837 as the earliest attempt at this kind of analysis. 
See page (91).* 

Endemann extracts petrolene from asphalt through distil- 
lation in a current of carbonic acid, at 225 250 C. The dis- 
tillate contains paraffine if any is present in the asphalt. He 
determines the petrolene in an asphalt by extracting 5 gms. 
with chloroform, filtering the solution and distilling off the 
chloroform in a weighed flask ; drying the residue for half an 
hour at 120 C. He then heats 0.2 to 0.3 gms. of this residue 
in a porcelain boat 12 hours at 250 C. in a stream of carbonic 
acid gas. The loss he calls petrolene, the residue asphaltene.t 
The significance of these terms has already been discussed. 
(See pages 98 and 101). 

Endemann further claims that if a chloroform solution of 
the total bitumens in an asphalt deposits a precipitate, it con- 
sists of the mineral salts of asphaltic acid. By means of filter- 
ing, drying and weighing the quantity can be estimated.^ 

METHODS OF SOLUTION. 

Le Bel extracts the bitumen with naphtha, which he dis- 
tills off, and then precipitates the "asphaltene" in the concen- 
trated solution with amyl alcohol. This precipitate may be 
dissolved in naphtha and precipitated a second time with amyl 
alcohol. The precipitate appears as a black resin from which 
ethyl ether will dissolve a red substance having the appear- 
ance of rosin. The substance insoluble in ether contains 
silica, iron, manganese and lime. 

Meunier places a suitable quantity of asphalt in a closed 
vessel, with a sufficient quantity of the solvent and after re- 
peated shaking leaves it to stand for some time. The solu- 
tion is filterd off through a dry filter and the contents of the 
filter washed with the solvent as long as the solvent is colored. 

*Ann. Chem. et de Phys., LXIV, 171; XCIII, 442. 

tJour. Soc. Chem. Ind., 1896, XV, 222-298; XVI, 121-126; XVII, 1003; 
Chem. Ztg., 1896, p. 987. 

$Jour. Soc. Chem. Ind., XVI, 121; Chem. Zentbl., 1897; I, 781. 
Bul. Soc. Chem., L. 359; Wagner Yahresbericht, 1889, p. 17. 



150 SOLID BITUMENS. 

The solvent is evaporated or distilled, and the residue dried at 
100 to a constant weight, preferably in a stream of dry car- 
bonic acid gas, to avoid possible oxidation. By drying and 
weighing the contents of the funnel, an estimate may be made 
of the impurities contained in the asphalt. The composition 
of these impurities may be ascertained by means of qualitative 
and quantitative chemical analyses.* 

R. Kayser separates the constituents of asphalt by means 
of successive extractions with alcohol (Sp. gr. 0.835), ether 
and chloroform, and obtains substances that are quite differ- 
ent in both composition and properties. f 

Capt. Dolphus Torrey has described a number of experi- 
ments with solutions of asphalt in alcohol. He found that 
alcohol at different temperatures was readily saturated with 
a portion of the asphalt that was partially deposited in a red 
precipitate when the solution cooled. The alcohol remained 
cloudy and might be cleared by filtering. Capt. Torrey sat- 
urated muslin in a chloroform solution of the asphalt and then 
exhausted the muslin strips with alcohol. He obtained a very 
viscous extract, but does not appear to have reached definite 
quantitative results. 

In a series of experiments that the author carried on in 
California upon natural California asphalts and residuums 
from California petroleums, it was found that methyl, ethyl 
and amyl alcohols dissolved the constituents of asphalt in an 
increasing ratio and that the amount dissolved by either sol- 
vent varied with the temperature and the percentage strength 
of the alcohol. *The differences in the amounts dissolved 
varied so greatly under slightly changed conditions that all at- 
tempts to obtain quantitative results by the use of any variety 
of alcohol, as a solvent, were finally abandoned. The ma- 
terial dissolved out of the different natural asphalts and arti- 
ficial residuums by either of the alcohols was in every case 
precipitated in red drops of very viscous fluid, whenever the 
alcoholic solutions were diluted with water. I am not aware 
that the composition of this red liquid has been investigated.! 

Comptes Rendue, CXXIII, 1327-29; Chem. Zentralb, 1897, p. 399. 

tAnn. Crem. Pharm., LVIII, 273; Chem. u. Tech. d. Nat. u. Kunst. 
Asphalte, p. 858. 

|D. Torrey, Physical Properties of Asphalts, Paving and Municipal Engi- 
neering, May, 1894; Sept., 1894. 

S. F. Peckham, Jour. Frank. Inst., Mar., 1896. 



TECH X 1C 'A L ANALYSIS CP SOLID BITUMENS. 151 

Another neutral liquid that is closely allied to the alcohols 
and that may easily be obtained pure and dry is acetone 
dimethyl ketone. I think its use as a reagent in the analysis 
of asphalt was first suggested by Dr. S. P. Sadtler. He ob- 
jects to the method proposed by Miss Linton (page 154) as 
tedious, and describes the following method as a substitute : 

"An asbestos filter is made in a weighed Gooch crucible 
and dried. About 10 gms. of fine white sand, previously ig- 
nited and cooled, are added, and a piece of stout platinum wire, 
about 3 in. long, is placed in the crucible and the whole dried 
to a constant weight at 100 C. 

"Then I to 2 gms. of the asphalt, in fine powder, if a solid, 
are added, gently mixed with the upper portion of the sand 
layer with the aid of the platinum wire, care being taken not 
to disturb the asbestos filter below. The weight of the whole 
is accurately taken, inclusive of the wire and the crucible, and 
its contents then dried at 100 C. to a constant weight, either 
in an air bath or water oven, cooled in a desiccator and 
weighed. If the sample be a maltha (liquid bitumen), it is 
gently mixed with the sand layer, after slightly softening it 
with the aid of the drying oven. The loss at 100 C. is calcu- 
lated and called 'moisture and loss at 100 C.' The crucible 
and its contents are then placed in a continuous extraction 
apparatus, formed by placing a small percolator within a 
larger one, the inner one being held in position by a perforated 
cork. The crucible having been placed in the inner perco- 
lator, the outer one is connected with a flask containing the 
solvent, and with an upright condenser. The flask is heated 
either on a sand bath or a water bath, the former being pre- 
ferable, since when once regulated it needs no attention or 
renewal as does the water bath. The extraction with acetone 
which is first undertaken, is continued until the loss on ex- 
tracting for two hours is not more than I or 2 milligrams. 
The loss of weight after this extraction, as compared with the 
weight on starting the extraction is calculated and called 
'petrolene.' The extraction is then continued in the same 
manner with chloroform, and the final loss is the 'total bitu- 
men.' The time necessary to effect a thorough extraction 
varies greatly with the different asphalts, but it will not 
amount to more than twelve hours for the acetone and eight 



152 SOLID BITUMENS. 

hours for the chloroform extraction. The loss in weight 
should be taken first after four hours, and then every two 
hours until the extraction is complete, the crucible and con- 
tents being dried at 100 C, and cooled in a desiccator each 
time. The residue in the crucible then represents the organic 
non-bitumen and mineral matter. It is ignited, after placing 
the cap on the bottom of the crucible, and the loss calculated 
as 'organic non-bitumen', while the remainder is the 'mineral 
matter' or 'ash.' "* 

In a paper read before the Franklin Institute of Philadel- 
phia, January, 1896, I showed that the solvent effects of 
acetone upon asphalts approached those of alcohols and were 
quite different from those of petrolum ether; for which reason 
acetone could not be substituted for petroleum ether in the 
analysis of asphalts, unless a new series of constants was 
established. 

It was further shown in that paper that an acetone solu- 
tion of Trinidad pitch, evaporated to dryness at about 60 C. 
yielded an organic residuum and deliquescent salt, which 
when dissolved away by water from the bituminous and very 
viscous residue, and evaporated to dryness, yielded an organic 
residue soluble in water. A portion of crude Trinidad pitch, 
exhausted with petroleum ether and chloroform, yielded to 
acetone a residue, a part of which was soluble in water, a part 
in sodium hydrate and a part in benzole. One gram of crude 
Trinidad pitch, after exhaustion in chloroform, yielded i.;<j 
per cent material soluble in acetone. 

Equal portions of a very dry Egyptian asphaltum and an 
Athabasca River maltha, were exhausted with petroleum ether 
and with acetone, with the following results : 

Egyptian Athabasca 

Asphaltum Maltha 

Percent. Percent. 

Petroleum ether, soluble 38.03 73.8(i 

Acetone, .soluble 8.68 2433 

No difference was observed between thfc solvent powers of 
cold and boiling acetone in either case. The dry Egyptian 
asphaltum and the semi-fluid maltha exhibit the extremes to 



*S. P. Sadtler, Jour. Frank. Inst., Nov , 1895. 



TECHNICAL ANALYSIS OI- SOLID lUTi'MLXS. .-3 

\vhich any solvent of bitumen is likely to be applied and the 
lack of parallelism is enormously large in both cases. 

Later experiments upon Trinidad pitch have led to the 
conclusion that after exhaustion with water a clearly defined 
portion of the pitch is soluble in 95 per cent methyl alcohol. 
The solution is slowly accomplished and the amount of the 
soluble required to saturate the alcohol is comparatively small. 
So far as the soluble has been examined it is a reddish brown, 
semifluid body of great viscosity. It is readily acted on by 
a mixture of nitric and sulphuric acids, forming a nitro deriva- 
tive of a deep red-orange color, heavier than water.* 

After exhaustion with methyl alcohol a portion of the 
pitch many times larger is found to be soluble in pure dry 
acetone. This soluble is a very dense, slightly mobile, very 
viscous fluid, of a deep, cherry-red color. This body, too, 
will form a dense nitro compound with a mixture of nitric and 
sulphuric acids. 

E. Jacobsen separated the soluble from the insoluble con- 
stituents of Syrian asphalt by the use of petroleum benzine 
(petroleum ether). He dissolves the asphalt in the least pos- 
sible quantity of "coal tar benzol" (benzene), filters the. solu- 
tion and pours it into ten times the volume of petroleum ben- 
zine (sp. gr. 0.690 to 0.700). A precipitate is produced, which 
is gathered upon a filter and washed with petroleum ether (sp. 
gr. 0.650 to 0.660) until it passes colorless. The precipitate is 
weighed. f 

Dr. Holde uses a method of precipitation. He shakes 
thoroughly 1.5 to 5.0 gms. of the bitumen in a i-liter flask of 
colorless glass, with 300 to 500 c.cm. of benzine of the lowest 
possible boiling point, as the solubility of the asphalt decreases 
with the lowering of the boiling point. After standing at 
least a day, decant the larger part of the solution through a 
folded filter. Then bring the larger part of the precipitate 
upon the filter and rinse the flask with pure benzine until the 
filtrate no longer gives a residue upon evaporation. Dissolve 
the asphalt from the filter with pure hot benzole, then rinse 
the solution into a flask and distill off the larger part of the 
benzole, pour into a tared dish, evaporate the remainder of the 

*Jour. Frank. Institute, March, 1896. 
tChem. Ind., 1879, p. 369. 



I 5 4 SOLID BITUMENS. 

benzole, dry at 100 C. and weigh. The solution of the as- 
phalt from the filter must be made as soon as possible, in order 
to avoid any increase in weight from oxidation or absorption 
of hygroscopic moisture.* 

Carl Engler has assumed that all crude petroleums con- 
tain paraffine, asphalt and pitch, which accumulate in the 
residuums from distillation. He assumes that maltha (Berg- 
teer) and that which is related to natural asphalt (Erdpech) 
as produced from petroleum, include these principal con- 
stituents. Asphalt is that which is insoluble in the lightest 
Ligroin (the lightest distillate from petroleum gasolene) and 
pitch is the part most easily soluble therein. At Engler's sug- 
gestion A. Flachs has worked out a method of separating 
these substances, which is based upon the process of Holde 
as well as upon an earlier research of Engler and Bohm. This 
research assumes that the original mixture, or a substance 
containing it, shall be dissolved in benzole and ether and the 
solution precipitated by alcohol. The pitch as well as the 
asphalt both dissolve in benzole and ether, and are both pre- 
cipitated together by the alcohol. On filtering, the paraffine 
and oil in the solution may be determined by any known 
method. The precipitate may be extracted with Ligroin, of 
not more than 45 boiling point; the pitch passes into solu- 
tion and may be determined by distilling off the solvent. The 
asphalt remains as a deep black insoluble powder, f 

The same objections may be urged against the terms 
"asphalt" and "pitch" that have been urged against "petro- 
lene" and "asphaltene." These "substances" as described are 
not identical in composition when obtained from different 
crude materials. 

In 1894 Miss Laura A. Linton published a paper, which 
I quote entire. 

"In the year 1837, J. B. Boussingault published his cele- 
brated memoir on the "Composition of Bitumens." In the re- 
searches upon which this memoir was based he had discovered 
that certain bitumens yielded in one manner a portion of their 
content and in another manner another portion of their con- 

""Lunge's Chem. Tech. Untersuchungs Mothoden, 1905, iii, p. 13. 
t-gl. Nachtrage uber den Bergteer von Pechelbronn; Inaugural disserta- 
tion, Basle, 1902; Lunge Chem. -Tech., 1905, iii, 13. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 155 

stituent hydrocarbons. He called the first portion 'petrolene' 
and the second portion 'asphaltene.'* 

"In i827f Le Bel and Muntz went over the same ground 
and in 1883 Le Bel again went over it, adding a few facts in 
relation to other bitumens than those previously examined but 
leaving the two substances, petrolene and asphaltene, practi- 
cally where he found them.t 

"In 1837 the conclusions based on chemical research were 
<ar less exact than at the present time and Boussingault con- 
cluded that the substances, petrolene and asphaltene, were 
simple substances and also that they were identical from what- 
ever sources they were derived. In this conclusion Le Bel in 
a measure appears to coincide. 

"It, however, requires no argument to prove, to any one at 
all familiar with the subject, that petrolene is nothing but a 
name that c'overs a great variety of substances, radically un- 
like, that exist in different forms of bitumen and are only re- 
lated, in this instance, as being held in solution by a certain 
limited number of menstrua and which include the whole 
list of paraffines and iso-paraffines, the defines, the benzines 
and additive benzines with many other less abundant and 
well-known substances. 

"Ethyl ether and so-called petroleum naphtha, which lat- 
ter is an indefinite mixture of fluid paraffines and iso-paraffines 
of high specific gravity, are the solvents used ; but no deter- 
mination has been made as to the influence of proportion in 
the mixtures of the substances dissolved, or as to the relative 
solvent powers of the two menstrua upon the different con- 
stituents of these mixtures. In fact petrolene is nothing but 
a name which at present covers a vast expanse of the un- 
known. 

"It can be safely said that probability favors the assump- 
tion that asphaltene is a little more definite; but no certainty 
attaches to the identity of asphaltene from different sources 
or of asphaltene dissolved by different menstrua. 

"Therefore, in a general way, it may be said that as- 
phaltene is that portion of the different forms of bitumen that 

*Annales de Chemie et de Physique, Ixiv, 141. 
tBull. Soc. Chem., 17, 156. 
JIbid, 50, 359. 



156 SOLID BITUMENS. 

is soluble in carbon disulphide, chloroform, benzine and a few 
other less well-known liquids and is not soluble in the men- 
strua that dissolve petrolene. 

"As the bitumens examined by the French chemists, 
above mentioned, have never assumed commercial importance, 
the questions relating to petrolene and asphaltene have re- 
mained matters of scientific interest only. However, since 
asphalt paving has become a business involving the expendi- 
ture of large sums of money these problems are beginning to 
assume a wide importance outside the laboratory of the chem- 
ist and to demand from technologists very serious considera- 
tion. Within recent years large numbers of so-called analyses 
have been reported, which represent various attempts to de- 
termine and set forth the relative value of many samples and 
kinds of asphaltum, that may or may not be suitable for the 
many uses to which asphaltum is applied, but more particu- 
larly with reference to street paving. Prominent among the 
chemists who have been more or less extensively engaged in 
these analyses of asphalts are Mr. Clifford Richardson, Dr. 
Henry Leffmann, Dr. Samuel P. Sadtler, and Dr. De Smedt. 

"A perusal of the numerous published reports of Mr. 
Richardson reveals the fact that in his tests the solvents used 
for the extraction of petrolene and asphaltene, were petroleum 
ether and carbon disulphide, while Drs. Leffmann and Sadtler, 
in their investigations and tests of asphalts, used alcohol- 
presumably ethyl-alcohol carbon disulphide, and ether as 
shown by the report submitted to the Citizens' Municipal As- 
sociation and the Trades League of Philadelphia. 

"Neither of these gentlemen describe any process or 
method employed in obtaining the results stated. It is hardly 
consistent with the nature of the reports that they should. 
Nor has Mr. Richardson, in an aricle published in the Journal 
of Analytical and Applied Chemistry, in the numbers for De- 
cember, 1892, and January, 1893, given any detailed descrip- 
tion of the process he employed in order to obtain the numer- 
ous results of analysis that he there uses. 

"But little satisfaction can be derived from consulting 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 157 

Allen's encyclopedic work so exhaustive upon every subject 
relating to technical organic analysis.* 

"We find therein the following statements and notes con- 
cerning the solvents and methods used in the analysis of as- 
phalts: Tor the determination of the total bituminous mat- 
ters in asphalt rock and mixtures containing it, C. T. Kingzett 
extracts the air-dried sample with freshly distilled Russian 
oil of turpentine, evaporates (Analyst viii, 4) the resultant so- 
lution and weighs the residue. The matter insoluble in turpen- 
tine is washed with ether, the calcium and magnesium car- 
bonates dissolved in hydrochloric acid and the washed in- 
soluble siliceous matter weighed/ 

" 'H. P. Cooper prefers carbon disulphide for dissolving 
out the bituminous matters from asphaltic mixtures/ 

"Allen adds in a .note, The carbon disulphide employed 
for dissolving the bituminous matter must not contain free 
sulphur. It may be replaced by chloroform or benzene (coal 
tar naphtha). If the residue left after extraction be dark col- 
ored, foreign organic matters of valueless nature are present. 
Their proportions may be determined by igniting the weighed 
residue left after dissolving out the asphaltum, recarbonating 
it with ammonium carbonate, again gently heating it and re- 
weighing. The loss of weight is the amount of non-bitu- 
minous organic matter present. In the case of samples leav- 
ing a white residue after exhaustion with carbon disulphide, 
the bituminous matter may be simply and accurately ascer- 
tained from the loss on ignition, taking care to recarbonate the 
lime before weighing/ 

"In another note, page 377, he says : 'Five grams of the 
finely divided sample were digested for one hour with fifty c.c. 
of petroleum spirit (sp. gr. 0.7) and the mixture frequently 
agitated. The liquid is then boiled for a short time, decanted 
and the residue boiled with another quantity of twenty-five cc. 
of petroleum spirit. This treatment is repeated eight or ten 
times until the exhaustion is complete. 

; "E. Davies (Pharm. Jour., [3], 14, p. 394), reports that 
none of the organic matter in Val de Travers asphalt is insolu- 
ble in petroleum spirit/ 

"Commercial Organic Analysis, by Alfred H. Allen, London, 1886, 2, 375-7, 
and later editions. 



158 SOLID BITUMEXS. 

"Now, when we take into consideration the fact that tur- 
pentine, carbon disulphide, ether, chloroform and benzine have 
been used indiscriminately by chemists in the extraction of 
asphaltene, the question very naturally arises, are the results 
that have been and that are being- obtained by these different 
methods of analysis strictly comparable that is, are they con- 
vertible terms? Will the same asphalt treated with different 
solvents show in each case the same percentage composition? 
If not, then it is evident that asphalt taken from different lo- 
calities and subjected to dissimilar methods of analysis cannot 
yield results of any value so far as purposes of comparison 
are concerned. Then again, if turpentine, carbon disulphide, 
and chloroform give a different proportion of asphaltene in 
the same asphalt it is just as evident that asphaltene, instead 
of being a definite chemical substance, is a mixture, which 
mixture would doubtless vary in different asphalts. 

"It was for the purpose of determining whether petroleum 
ether (paraffines), California naphtha, and ethyl ether are 
interchangeable solvents of petrolene and whether turpentine, 
carbon disulphide and chloroform are interchangeable solvents 
of asphaltene that the research, the results of which are here 
given, was undertaken. That a series of such tests, faithfully 
carried out, should lead to the establishment of a method of 
analysis applicable to all asphalts and, at the same time, reveal 
something regarding the real nature of petrolene and asphalt- 
ene was inevitable. 

"The specimens analyzed were furnished me by Prof. S. 
F. Peckham, Chemist of the Union Oil Co. of California, and 
were as follows : 

"(i) Crude Trinidad Asphaltum. From the Warren- 
Scharf Asphalt Co., of New York City. This specimen con- 
tained little or no water, as, for several months, it had been 
broken in small pieces, and so had lost the water which this 
asphaltum generally contains. 

"(2) Cuban Asphalt. A commmercial sample obtained 
in New York City. 

"(3) Kuban Residuum. An artificial asphalt obtained 
from the distillation of Kuban petroleum from the western ex- 
tremity of the Caucasus Mountains, Russia. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 159 

"(4) Egyptian Asphalt. An Assyrian asphalt taken 
from the Dead Sea and imported into Egypt. This specimen 
was obtained in New York City. 

"(5) Asphaltic Rock. From Val de Travers, Switzer- 
land. This asphalt was a sample of natural rock obtained at 
the office of Wm. H. Delano, representative of the French 
Company in New York City. 

"(6) Seyssel Asphaltic Rock. From the well-known lo- 
cality in eastern France, obtained from the same source as 
No. 5. 

"(7) Turrellite. From a deposit lately discovered in 
Uvalde County, Texas, consisting of a mass of sea-shells ce- 
mented together by bitumen into a solid rock mass. It oc- 
curs in a rock formation said to be of Jurassic age, in which 
formation the Val de Travers rock also occurs. This speci- 
men was obtained from the office of the Litho-carbon Co. of 
New York City. 

"(8) Kentucky Asphaltic Rock. Obtained from Mar- 
shall Morris, Louisville, Ky. 

"(9) An Asphaltic Mineral. Resembling Gilsonite; re- 
ported as coming from Utah. 

"(10) California Maltha. Taken from a well at Sum- 
merland, on the coast, near Santa Barbara. 

"(11) Asphaltum. From mines recently opened near 
Asphalto, Kern County, California, in the eastern foothills of 
the Coast Range Mountains, about thirty miles west of Bak- 
ersfield. 

"(12) Asphaltic Sandstone. From San Luis Obispo, 
Cal. 

"(13) Asphaltum. Picked up on the beach at San 
Buena Ventura, Cal., washed in from the Santa Barbara chan- 
nel. 

"(14) Asphaltum. From the Ojai ranch, Ventura Co., 
Cal. 

"(15) Grahamite. A so-called asphaltum taken irom a 
vein in Ritchie Co., W. Va. 

"(16) A portion of a compressed brick made from the 
asphaltic rock taken from the Seyssel mines. Exhibited at 
the Columbian Exposition, 



l6o SOLID BITUMENS. 

<4 (i7) Hard Artificial Asphalt. An asphaltic residue 
obtained from the distillation of petroleum obtained near 
Santa Paula, Cal. It is known in the refinery of the Union 
Oil Co., of California, as grade "B." 

"(18) Soft Artificial Asphalt. From the refinery of the 
Union Oil Co., of California, at Santa Paula. Grade "D." 

"(19) Asphaltic Pavement. Obtained from Franklin 
avenue, Buffalo, N. Y. It was laid in 1878, of Trinidad as- 
phalt, wax tailings, and very fine sand. It is remarkable as 
having been laid for 15 years with almost no need of repairs. 

"(20) Asphaltic Pavement. From Governor's Island, 
New York Harbor, laid within the fort at an unknown date, 
but so old that it has begun to break up from natural causes. 
Obtained from J. A. W. Pine, of Xew York City. 

" '(21) Dubb's Artificial Asphalt. A so-called asphaltum 
obtained in operating the Dubb's patent process for the man- 
ufacture of asphaltum by adding sulphur to hot Lima-tar and 
thereby burning out the hydrogen. This is an asphalt only 
in name. The specimen was obtained from J. A. W. Pine, of 
New York City. 

"(22) Roofing Pitch. Obtained from Mica-asphalt Co., 
of New York City. 

"(23) Pitch. Obtained as a residuum in the distillation 
of Scotch blast-furnace tar. This specimen was obtained from 
the same source as Nos. 20 and 21. 

"In making tests to determine the best methods to be 
used in the analysis of asphalts the well known Trinidad and 
Cuban asphalts were used and all analyses were made in 
duplicate. In the case of asphalts rich in bituminous matter 
about a half gram of the material, finely powdered, was used 
but in the case of asphalts in which the mineral matter con- 
stituted a large proportion the quantity was increased to 
several grams. 

"The sample was weighed in an Erlenmeyer flask and 
digested over night in about fifty c. c. of petroleum ether ; in 
the morning the clear solution, containing the dissolved 
petrolene, was passed through a balanced filter and a fresh 
portion of petroleum ether added to the contents of the flask. 
The second digestion was continued for two or three hours 



TECHX1CAL ANALYSIS Ol< SOLID BITL'MEXS. : 6i 

when the solution, as before, was filtered off and the process 
repeated until the whole of the petrolene had been removed. 
The contents of the flask were then thrown upon the filter 
and thoroughly washed with petroleum ether. Cold turpen- 
tine was then poured upon the filter in successive portions 
until the filtrate passed through colorless when the assump- 
tion was made that all the asphaltene and consequently all 
the bituminous matter had been removed. 

"The remaining organic matter, not bituminous, was de- 
termined by difference, that is, the residue on the filter, after 
digestion in turpentine, was washed with ethyl alcohol, dried, 
and weighed in order to determine the percentage of as- 
phaltene after which the residue was burned in a platinum 
crucible, the difference in weight representing the organic 
matter not bituminous. 

"The contents of the crucible were now purely inorganic 
and, in the case of most asphalts, the residuum was sand more 
or less colored with iron. 

"The analysis of Trinidad asphalt under this treatment 
gave so low a percentage of asphaltene and so large a pro- 
portion of organic matter not bitumen, that it was clearly evi- 
dent that cold turpentine had not dissolved, and could not 
dissolve all of the asphaltene. 

"A second set of experiments was then tried in which 
cold turpentine and carbon disulphide were used as solvents 
of asphaltene. The results obtained for samples I and 2 were 
as follows : 

Other organic "Mineral 
Sample. Petrolene. Asphaltene. matter. matter. Total. 

No. 1 32.54 20.3435 12.368 34,6775 99.929 

No.2 25.049 54.53 2.441 17.9215 99.9415 

"The experiment was now made of somewhat varying 
the method of treatment for the following reasons: First, 
because of the difficulty of dissolving out the asphaltene while 
on the filter by simply allowing the solvent to run through 
it, and secondly, because, in consequence of the high specific 
gravity of petroleum ether, a considerable portion of sand or 
other mineral matter, mixed with asphaltene, always adhered 
to the flask, thus necessitating a separate determinaiion of 
this portion. The method now employed for the removal of 



162 ' SOLID BITUMEXS. 

petrolene and asphaltene was the decantation method, and 
the solvents used for asphaltene were hot turpentine and 
chloroform. 

"The samples were digested over night in petroleum 
ether; in the morning the solution containing the petrolene 
was, as far as practicable, removed from the flask and the 
remainder was evaporated over a steam-bath ; after weighing, 
the residuum containing the asphaltene was digested in hot 
turpentine over the steam-bath, and finally, the whole con- 
tents of the flask were poured upon a balanced filter and 
treated as in the first experiments. 

"The percentage composition of Nos. I, 2, and 17, as 
determined by the decantation method, was as follows: 

Other organic Mineral 

Sample. Petrolene. Asphaltene. matter. matter. Total. 

No. 1 31.51 22.9865 11.4195 34,073 99.989 

No. 2 25.055 52.245 5.758 16.918 99.962 

No. 17 64.571 21.2545 13.706 0.3613 99.8928 

"In carrying out this method a great many determina- 
tions were lost, due to the fact that, in evaporation to dry- 
ness over the steam-bath, the contents of the flask were in 
part bumped out. In consequence, this method was soon 
abandoned as impracticable, and finally, funnels with stop- 
cocks were employed, in which the contents of the filter could 
be digested. Boiling hot instead of cold turpentine was used, 
and, when necessary, the digestion was continued over night, 
and all the after washings were made with hot turpentine. 
Numerous trials showed that carbon disulphide dissolves little 
more than hot turpentine. The last trace of asphaltene, in- 
soluble in either turpentine or carbon disulphide, was removed 
by chloroform. 

"In order to determine the relative solvent power of hot 
turpentine, carbon disulphide, and chloroform, the foliowing 
method of qualitative analysis was applied to the twenty-three 
samples enumerated above. From a half gram to one gram 
of the material was digested over night in a four-ounce Erlen- 
meyer flask with about fifty c. c. of petroleum ether. Next 
morning the contents of the flask were pourned upon a filter, 
and the undissolved residue washed with petroleum ether 
until the filtrate was no longer colored. Boiling spirits of 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 163 

turpentine was then poured upon the filter until it passed 
through colorless, when carbon disulphide was used in the 
same manner, followed lastly by chloroform. The action of 
the successive solvents is shown in the following table: 

Sample. Hot turpentine. Carbon disulphide. Chloroform. 

No. 1. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 2. Dissolves a large Dissolves a consider-Dissolves a perceptible 

amount. able amount. amount. 

No. 3. Dissolves nearly all. Dissolves a trace. Dissolves a trace. 
No. 4. Dissolves nearly all. Disolves the slight- Dissolves the slightest 

est trace. trace. 

No. 5. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 6. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 7. Dissolves nearly all. Dissolves the slight- Dissolves the slightest 

est trace. trace. 

No. 8. Dissolves nearly all. Dissolves the slight- Dissolves a trace. 

est trace. 

No. 9. Dissolves nothing. Dissolves nothing. Dissolves a trace. 
No. 10. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 11. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 12. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 13. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 14. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 15. Dissolves a large Dissolves a consid- Dissolves a consider- 

amount. erable amount. able amount. 

No. 16. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 17. Dissolves a large Dissolves a consid- Dissolves a consider- 

amount. erable amount. able amount. 

No. 18. Dissolves a large Dissolves a consider-Dissolves a consider- 

amount. erable amount. able amount. 

No. 19. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 
No. 20. Dissolves nearly all. Dissolves a trace. Dissolves a perceptible 

amount. 

No. 21. Dissolves nearly all. Dissolves a trace. Dissolves a trace. 
No. 22. Dissolves a large Dissolves a consider-Dissolves a trace. 

amount. erable amount. 

No. 23. Dissolves a large Dissolves a consider-Dissolves a consider- 
amount. erable amount. able amount. 

"Of the twenty-three asphalts examined, there was not 
one that did not yield some asphaltene on treatment with 
chloroform; consequently, it is safe to infer that in the an- 
alysis of asphalts, unless final washing be made with chloro- 
form, the per cent of asphaltene will be too low. There was 



164 SOLID BITUMENS. 

a marked difference observed in the different asphalts as to 
the manner in which their constituent asphaltene was dis- 
solved on treatment with hot turpentine. In Nos. 4, 5, 6, and 
7, and a few others, the asphaltene dissolved out in a few 
minutes, while in the case of others, notably No. 15, it was 
a matter of hours, and even of days, before every trace solu- 
ble in turpentine could be removed. No. 9 seems to be an 
asphaltic freak as it contains no petrolene whatever and is 
insoluble in both hot turpentine and carbon disulphide, while 
chloroform and amylic alcohol dissolve but the slightest trace. 

"It was a difficult matter to determine the relative quan- 
tity of asphaltene dissolved by the different menstrua, as the 
only guide used was the color of the filtrate. This suggests 
a most interesting research the fractional, quantitative de- 
termination of asphaltene. 

"From my experience in the analysis of asphalts, I would 
advise that a preliminary qualitative analysis be always made 
of each new variety of asphaltum before any quantitative de- 
terminations are attempted, care being taken to observe the 
behavior of different asphalts with the different solvents. 
This method of procedure is to be recommended, not only 
because it would prove an economy of time and reagents used, 
but also because, in this way, much would be learned con- 
cerning the nature of petrolene and asphaltene. 

"A trial was made with Cuban asphalt to determine the 
solvent power of petroleum ether (87 Beaume) as compared 
with that of California naphtha (74 Beaume) and ethyl ether 
with the following results: 

Sample. Solvent for petrolene. Per cent of petrolene. 

No. 2. Petroleum ether 25.8516 

No. 2. California naphtha 32.444 

No. 2. Ethyl ether 32.5455 

"The high percentage of petrolene when California 
naphtha or ethyl ether are used indicates that the asphaltene 
is, in part, dissolved, and consequently, that these menstrua 
cannot be used as solvents of petrolene in the determination 
of asphalts. 

"In selecting a method for the quantitative analysis based 
upon the results of these experiments, it is assumed that, until 



TECHNICAL ANALYSIS OP SOLID BITUMENS. 165 

a strictly scientific method is worked out, the present em- 
pirical determination of petrolene and asphaltene will con- 
tinue in use. The three considerations of economy, speed, 
and convenience, will together control the selection. So long 
as the significance of the difference between the 25.8 per cent 
dissolved by petroleum ether and the 32.5 per cent dissolved 
by ethyl ether is an unknown element in the problem that 
is, whether it be seven per cent of petrolene or of asphaltene 
that is involved it is better to use petroleum ether, because 
it is cheap and easily obtained of a uniform quality. So, too, 
it is better to use boiling hot turpentine followed by chloro- 
form as solvents of asphaltene, and thus rid ourselves of car- 
bon disulphide altogether. 

"With these considerations in view the following method 
of analysis is recommended: 

"Weigh two suitable portions in four j ounce Erlenmeyer 
flasks, add fifty c. c. of petroleum ether, cover, and allow to 
stand over night. The following morning decant the liquid 
upon a balanced filter placed within a three-inch funnel pro- 
vided with a stop-cock in the neck. Add another portion of 
petroleum ether to the flask, allowing two or three hours for 
digestion, and decant the liquid upon the same filter as before ; 
this process is to be continued until the liquid ceases to be 
colored, then transfer the whole of the bitumen to the filter. 
Dry the flask in, a steam-bath and weigh; any increase in 
weight of the flask should be subtracted from the amount 
determined as petrolene. Wash the filter and its contents 
with petroleum ether, place these with the filter counterpoise 
in a steam-bath, dry, and weigh; the loss in weight of the 
bitumen represents the petrolene. 

"Rinse the flask thoroughly with boiling turpentine and 
add the liquid to the filter in the closed funnel, pour upon the 
filter a sufficient quantity of boiling turpentine to wholly sub- 
merge it, cover and allow the digestion to continue for sev- 
eral hours or over night. Repeat the digesting and filtering 
with boiling turpentine until the filtrate becomes Colorless. 
The filter should be much smaller than the funnel. Rinse 
the flask with chloroform and pour upon the filter, add suf- 
ficient chloroform to wholly submerge the filter and allow at 



i66 



SOLID BITCMEXS. 



least an hour for digestion; wash with chloroform until the 
filtrate passes through colorless, then dry and weigh ; the 
loss in weight represents the asphaltene. The filter is now 
to be burned in a platinum crucible and, if the asphaltum be 
combined with limestone, the residue recarbonated with am- 
monium carbonate, dried in a steam-bath, and weighed, the 
loss in weight represents the organic matter not bitumen, or 
coke, in the case of artificial asphaltic residuum, produced by 
heat. 

"There is necessity for washing the flask with the differ- 
ent solvents, not only because the petroleum ether is too light 
to rinse out all of the mineral matter, but also because some 
of the asphaltene adheres to the flask. Generally the !~urpen 
tine removes all of the mineral matter, as well as part of the 
asphaltene, but if it does not, then after the flask is rinsed 
with chloroform it must be again dried and weighed and the 
increase in weight added to the weight of the mineral matter 
in the platinum crucible. If water be present the asphalt 
should be dried in a steam-bath to a constant weight before 
being digested in petroleum ether. It is possible that some 
natural asphalts might experience a trifling less of volatile 
oils at the temperature of the steam-bath, but in most in- 
stances such loss would be too slight to be regarded. "With 
care and patience this method has been found capable of yield- 
ing very closely concordant duplicate results at each step. 

"The following table exhibits the results of a number of 
quantitative analyses made according to this method: 

Other 



Sample. 
No. : 
No. \ 
No. < 



Water. 
,. 2.029 
. 0.3911 



organic 
Petrolene. Asphaltene. matter. 



No. 5 

No. 6 
No. 7 
No. 8 
No. 12 
No. 15 
No. 17 
No. 18 
No. 19 
No. 20 
No. 21 



0.335 



0.434 



32.4455 
25.4605 
35.087 

8.&18 

7.486 

8.786 

3.349 

11.323 

49.959 

64,571 

63.498 

4.387 

6.666 

66.788 



22.1115 

54.414 

63.183 

3.924 

4.316 

3.267 

2.4215 

3.81 

50.041 

21.2545 

29.966 

2.831 

1.87 

31.932 



8.1215 

2.469 

1.7285 



Mineral 
matter. 
35.2865 
17.0305 



Total 
99.994 
99.7651 
99.9985 



Not recarbonated. 



25,791 



1.124 

13/706 
6.095 
4.102 
3.697 
1.278 



61.764 
88.198 
87.947 
94.228 
83.407 

0*3613 

88.65* 
87.33 



99.997 

100. 

100. 
99.9985 
99.999 

100. 
99.8928 
99.559 
99.97 
99.997 
99.998 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 167 

"While this research is in no sense complete it has in 
fact but opened up a wide field for further work yet, suffi- 
cient evidence has been obtained to show that petrolene and 
asphaltene are not substances, but empirical terms that desig- 
nate mixtures of substances soluble under certain conditions 
in different menstrua. 

"It is not unfair to assume that in these empirical mix- 
tures, so long known under the names of petrolene and as- 
phaltene, the lower members of all the different groups of 
hydrocarbons now known may be found. Again just as 
some petroleums, which are varieties of bitumen, consist 
chiefly of paraffines notably Pennsylvania petroleum and 
some, like Russian petroleum, consist of the additive benzines, 
while still others contain mixtures of the two, is it not rea- 
sonable to presume that solid bitumens, like liquid bitumens, 
are equally variable in composition? If this be the case, then 
it is equally fair to assume that any solvent taken will not 
dissolve substances of identical composition from' different as- 
phalts. 

"A review of the results here given suggests the query, 
have the methods heretofore employed for the technical an- 
alysis of asphaltum really been analytical at all? Would not 
a method and process suggested by the results of the quali- 
tative analyses given in this paper and based on the succes- 
sive application of different solvents and yielding results sim- 
ilar to those of fractional distillation really become analytical, 
especially if the separate portions dissolved by the different 
solvents were subjected to such treatment by oxidizing agents 
as would enable us by a comparison of the products of oxida- 
tion to determine to what groups of hydrocarbons the differ- 
ent substances dissolved respectively belong? 

"I take pleasure in hereby acknowledging my indebted- 
ness to the courtesy of Hon. Thos. R. Bard, President of the 
Union Oil Co., of California, for the use of the laboratory of 
the company while engaged in this research.* 

In March, 1896, Miss Linton published a second paper, 
from which 'I quote as follows : 

*Laura A. Linton, S. B., M. D.; Journal of the American Chemical So- 
ciety, Vol. XVI, Dec., 1894. 



l68 SOLID BITUMEXS. 

"The method universally employed for the determination 
of the incorporated water of asphaltum is that of estimating 
the loss in weight of the substance when exposed to a tem- 
perature of 100 C. The possibility of a loss of more or less 
of the inherent volatile matter when heated to such a high 
temperature must have occurred to every one engaged in the 
analysis of asphaltum. A series of experiments made during 
the past few months' has confirmed my suspicion that such is 
the case. 

"The experiment proper consisted in heating a weighed 
portion of asphaltum in a combustion tube, the general ar- 
rangement of the apparatus being the same as that employed 
in the determination of water in organic analysis. The tem- 
perature was gradually raised from the temperature of the 
room to that of boiling water. The tube was swept out be- 
fore and after heating with either dried air or dried hydrogen. 
Simultaneously with this experiment two other weighed por- 
tions of the same asphaltum were dried, one in an oven at 
100 C. to serve as a check upon that portion dried in the 
combustion tube, while the other portion was dried in the sun. 
"As the method of sun drying requires several days it 
was done in a room as free as possible from dust and, to in- 
crease the temperature and at the same time to exclude all 
foreign matter, the samples were placed in large watch glasses 
with watch-glass covers fitting loosely to allow of circulation 
of air. In this lens-like arrangement the maximum tempera- 
ture did not exceed 50 C. On cloudy days the drying was 
necessarily done in the oven below 50 C. 

"These experiments showed that the asphaltum tested did 
not oxidize below 100 C., as aspiration with dried air and 
dried hydrogen give the same results ; and also that all moist- 
ure is driven off below 50 C., while between 50 C. and 100 
C. a certain portion of oily matter is lost, this oil invariably 
collecting in drops about the mouth of the combustion tube. 
In the light of these facts it becomes clear that the old method 
of determining moisture, if it is to be determined at all, is in- 
correct since the percentage lost on heating the asphaltum to 
100 C. includes not only the water but also that part of the 
petrolene volatile below 100 C. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 169 

"The moisture associated with an asphaltum being hygro- 
scopic, as is evident from the fact that the same specimen car- 
ries a constantly varying proportion depending on atmos- 
pheric conditions, it should never be estimated as a constitu- 
ent part of the asphaltum, particularly in making analyses 
for purposes of comparison. 

"In making all of my recent analyses, as a preliminary, 
I have air-dried to a constant weight several grams of the 
sample to be analyzed before weighing out the portion to be 
treated with the different solvents, thus entirely excluding 
water from the percentage composition of the asphaltum. 

"A second departure from the method previously ?.;iven is 
a purely mechanical one. As a matter of convenience T have 
discarded the use of the Erlenmeyer flask, the substance being 
weighed out on balanced filter-papers instead. In this way 
all digestion is done in separatory funnels. This method of 
treatment is very simple and the results obtained are good, 
but care must be taken that the solution in the funnels does 
not become too concentrated before running off through the 
tap, otherwise the petrolene precipitates itself, more or less of 
it adhering to the outside of the filter-paper. To prevent this 
the petroleum ether may be drawn off every few minutes until 
the greater part of the petrolene has been extracted, after 
which it is. perfectly safe to allow the digestion to continue for 
hours in removing the final traces. 

"Lastly, I have obtained some interesting and, in my 
opinion, important results by fractionating the asphaltene, 
determining it in two portions : that soluble in boiling tur- 
pentine and that soluble only in chloroform. The process is 
a very tedious one on account of the difficulty of removing 
the very last trace soluble in boiling turpentine, but the re- 
sults that follow are a sufficient warrant for the expenditure 
of so much time, which, for the specimens analyzed, ranged 
from one to four weeks. In order to secure concordant re- 
sults in duplicate analyses I found it necessary to pursue the 
following course: 

"After the removal of the petrolene the residue on the 
filter was digested in boiling turpentine until the filtrate was 
colorless, when the contents of the filter were washed in alco- 



I/O SOLID BITUMENS, 

hoi and dried at 100 C. If, on drying, a black, semi-liquid 
substance separated from the mass, this was an indication 
that the turpentine fraction had not been entirely removed, in 
which case the process was repeated. In the most refractory 
specimens this treatment was applied many times. The tardy 
yielding to the solvent power of the turpentine is doubtless 
largely due to the fact that the turpentine does not readily pen- 
etrate the mass and it may be, also, that the chloroform frac- 
tion prevents the action of the turpentine just as gold protects 
silver from the action of nitric acid. The completion of the 
process is always indicated by the appearance of the dried 
residue which, after the complete removal of the turpentine 
fraction, is invariably a loose, brown powder without coher- 
ence. This treatment shows that part of the asphaltene 
soluble in boiling turpentine to be a black, viscous, semi- 
liquid substance resembling tar and having a melting point at 
or below 100 C. 

"Another fact, which may prove valuable as well as inter- 
esting, is clearly brought out in this fractionation of asphalt- 
ene and that is that not only do the 'aged' varieties of as- 
phaltum contain a larger percentage oT asphaltene but the tur- 
pentine fraction becomes a smaller proportion of the total 
bitumen while the chloroform fraction becomes larger. 

"An investigation of the table of the percentage composi- 
tion of the following varieties of asphaltum will confirm this 
statement : 

"(i) An average sample of land asphaltum from the 
island of Trinidad. 

"(2) Altered or 'aged' (iron pitch) Trinidad land as- 
phaltum. 

"(3) Altered or 'aged' Trinidad land asphaltum. 

"(4) An average sample of Trinidad lake asphaltum. 

"(5) An altered or 'aged' Trinidad lake asphaltum. 

"(6) An altered or 'aged' Trinidad lake asphaltum 

"(7) An altered or 'aged' (iron pitch) Trinidad lake 
asphaltum. 

"(8) Asphaltum from Montague Co., Texas. 

"(9) Turrellite from Uvalde Co., Texas. 

"(10) Asphaltum from near Ardmore, Oklahoma. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 



171 



"(11) Grahamite from Ritchie Co., W. Va. 

"(12) Seyssel asphaltic rock from eastern France. 



Sam- 
ple. Petrolene. 

1 33.73 

2... 33.574 



. . 21.362 

.. 35.40 

... 26.925 

. . 19.25 

... 22.25 

8 7.538 

9 8.786 

10 9.503 

11 49.959 

12... 7.486 



Turpen- 
tine 
fraction. 

15.67 

13.7 

15.2 

12.300 

18.613 

22.35 
9.785 
1.601 
3.267 
0.9905 

17.458 
3.945 



Chloroform Asphal 
fraction. tene. 

3.179 18.849 

9.627 23.327 

15.112 30.312 

5.287 17.587 

6.687 25.3 

10.962 33.312 



Ratio of 

chloroform Organic 
fraction to matter 
Total total not 

bitumen, bitumen, bitumen. 



12.54 
trace 
trace 
trace 



22.325 
1.601 
3.267 
0.9905 



32.583 50.041 
0.371 4.316 



52.579 
56.901 
51.674 
52.987 
52.225 
52.562 
44.575 
9.139 
12.053 
10.4935 
100.00 
11.802 



1:16 

1:6 

1:3 

1:10 

1:8 

1:5 

1:4 



1:3 
1:31 



11.528 

8.414 

9.85 

10.962 

11.237 

9.562 

8,937 



Mineral 
matter. 

35.886 

34.684 
38.375 
36.100 
36.537 
37.875 
46.4G2 
90.861 
87.947 
89.5065 



88.198 



"I am not yet prepared to say that the turpentine frac- 
tionation of asphaltene, if made in the case of the asphaltum 
obtainable from different parts of the world would indicate 
the relative 'aging' of the different varieties, but my experi- 
ence with Trinidad pitch inclines me to think that this will 
prove the case when such analyses are made."* 

In Vol. Ill, 1903, of the Proceedings of the American 
Society for Testing Materials, A. W. Dow, of Washington. 
D. C, describes a process for "Testing Bitumens for Paving 
Purposes," as follows: 

"Chemical Tests. There has been but little done that is 
of practical value in chemical tests on bitumens, and there is 
so much confusion in what has been done that it is difficult 
for any one without considerable experience and knowledge of 
the subject to distinguish what is of practical value. One 
source of confusion in the examination of asphalts by chemical 
means results from the careless statement of methods of an- 
alysis given in some of our standard textbooks. An example 
of this is found in Sadtler's 'Hand Book of Industrial Organic 
Chemistry,' page 42. He states : 

" 'When on the other hand the asphalt is to be considered 
with reference to its value for asphalt paving purposes, it is 
necessary to examine into the quality of the bitumen. For 



*Jour. Am. Chem. Soc., xviii, Mar., 1896. 



172 SOLID BITUMENS. 

this purpose the total bitumen (amount soluble in carbon di- 
sulphide), organic not bitumen, and ash are first determined. 
Then the amount soluble in petroleum naphtha (so-called 
petrolene) is ascertained. The difference between this and 
the total bitumen is called asphaltene. * * * Instead of 
petroleum naphtha and carbon disulphide, acetone and chloro- 
form may be used with advantage for extractions.' While 
there is but slight difference between the results obtained 
from carbon disulphide and those obtained by chloroform ex- 
traction, yet there is no similarity at all in the solvent power 
of acetone and petroleum naphtha, and for this reason the 
results are not comparable. By the exercise of a little care 
in the compiling of such books a great benefit would result 
to those who have not the time to go deeply into the subject. 
"An illustration of the confusion resulting from the intro- 
duction of acetone as a solvent is found in the second edition 
of Stillman's Engineering Chemistry, page 438. He here 
gives a method of analysis by which the asphalt is first ex- 
tracted with acetone, and then by chloroform as recom- 
mended by Sadtler, and calls the material extracted with the 
acetone petrolene. He then goes on to give the method of 
L. A. Linton (J. A. C. S. 18, 375), in which the asphalt is 
first extracted by petroleum ether, then turpentine, and after- 
ward with chloroform. He here speaks of the bitumen that 
has been extracted with petroleum ether as petrolene. If the 
bitumen soluble in petroleum ether is to be called petrolene, 
surely the same author should not make the mistake and call 
a totally different set of hydrocarbons, that are dissolved out 
by acetone by the same name. There is yet another class of 
bodies derived from asphalt that are known by the name of 
petrolene. In 1837 Boussingault subjected an asphalt to the 
process of distillation, naming the liquid that distilled off 
petrolene, and the residue left in the retort asphaltene. Dr. 
H. Endemann subjects asphalts to the Boussingault process, 
applying his terms to the distillate and residue which he ob- 
tains. Here are three distinct methods of separation applied 
to asphalts, each separation producing totally different com- 
plex compounds, yet the same terms, petrolene and asphalt- 
ene, are applied to the products obtained in each separation. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 



173 



This leads to so much ambiguity in the subject that I can see 
no way to right things but by the abandonment of the names 
petrolene and asphaltene. I would advise the use of the terms 
naphtha soluble, acetone soluble, etc., for the products ex- 
tracted with these solvents. 

"Still another error into which people are led by some 
literature on the subject when they first take up the study of 
asphalt is the belief that petrolene and asphaltene are each a 
definite chemical compound. The petrolene and asphaltene 
obtained in any of the processes mentioned are not simply 
compounds, but complex mixtures of many chemical com- 
pounds, and petrolenes and asphaltenes derived from different 
asphalts are totally different from each other in their com- 
position, and for this reason such determinations on asphalts 
can bear no relation whatever to their physical properties or 
suitability for paving. I cannot too highly recommend to 
all who are confused about the nomenclature and analysis of 
asphalts that they read the excellent chapter in the Bulletin of 
the University of Texas, No. 15 ('Coal, Lignite and Asphalt 
Rocks'), by Henry W. Harper. He discusses most compre- 
hensively the ambiguity of the method and nomenclature of 
this subject. His results on the bromine absorption applied 
to different so-called petroleums and asphaltenes are evidence 
sufficient that these complex compounds differ in composition 
in every asphalt. 

"Bitumen Soluble in Carbon Bisulphide. It is usually 
considered that all the cementing material of an asphaltic ce- 
ment is soluble in carbon disulphide, but there is good ground 
for the belief that this is only approximately true and that 
the carbon disulphide in some cases dissolves materials that 
play no more part in the cementing than so much sand, while 
in others it leaves part of the cementing material undissolved. 
As, however, we have no means at the present time of deter- 
mining the absolute quantity of cementing material in an as- 
phaltic cement, and as the quantity soluble in carbon disul- 
phide is as close an approximation as any, and this solvent is 
more generally used than any other, I advise adhering to its 
use. It is for this reason that the use of chloroform or tur- 
pentine, as advised by some analysts, because it dissolves a 



174 



SOLID BITUMENS. 



little more from asphalt than does carbon disulphide, is not 
only unnecessary, but not advisable. There are numerous 
methods applied to the extraction of asphalt with carbon di- 
sulphide, the important ones of which can be found in Allen's 
Commercial Organic Analysis, Vol. II, Part II. Most of 
these methods are based on separating the insoluble from the 
soluble matter by nitration, and no correction is made for 
finely divided material, other than bitumen, which passes 
through the filter. From investigation I find that more or 
less finely divided mineral matter and organic matter not 
bitumen passes through the filter. It is claimed by some that 
this mineral matter is all in chemical combination with bitu- 
men, but I often find in the examination of paving mixtures 
that the finely ground limestone which is used in the mixture 
is found in the filtrate. I also find that the filtrate from some 
asphalts invariably contains finely divided organic matter 
which will subside on standing. It is seen from the above 
that for a method to be the most accurate, filtration cannot 
be depended on, for even though the filtrate be evaporated off 
and burned, in which a correction for the mineral residue pass- 
ing the filter is made, the insoluble organic matter which has 
passed the filter is burned off and considered as bitumen. It 
is for this reason that a method in which a long subsidence 
is used is the most preferable. The following is a method 
which I find, from long experience, gives the most accurate 
results: The asphalt, or like substance, is spread in a thin 
layer in a suitable dish (nickel or iron will do) and kept at a 
temperature of 225 F. until it practically stops losing in 
weight. The greater part and in some cases all the water and 
some light oils are expelled in this way. From 2 to 10 gms. 
(depending on its richness in bitumen) of this substance is 
weighed in a large-sized test-tube (8 ins. long by I in. in di- 
ameter), the tare of which has been previously ascertained. 
The tube containing the substance is then filled to within 1^2 
ins. of the top with carbon disulphide and allowed to stand 
for a few minutes. Then the tube is tightly corked with a 
good sound cork. It is then shaken vigorously until no asphalt 
can be seen adhering to the bottom. Care should be taken 
when shaking to keep one finger on the cork to prevent its 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 175 

being blown out. The tube should then be put away, still 
corked, in an upright position, and not disturbed in the slight- 
est way for two days, after which the carbon disulphide is 
decanted off into a second tared tube. As much of the sol- 
vent should be poured off as is possible without losing any of 
the residue. The first tube is again filled with fresh carbon 
disulphide and shaken as before and put away for two more 
days. The second tube is also corked and put away in an up 
right position. At the end of two days the contents of these 
two tubes are decanted off onto a weighed Gooch crucible 
fitted with an asbestos filter, the contents of the second tube 
being passed through the filter first. The residue in the sec- 
ond tube is then treated with about 2 c.c. of carbon disulphide, 
care being exercised to disturb it as little as possible, the 
treatment being to remove the small portion of solvent con- 
taining bitumen. The Gooch crucible is then washed with clean 
carbon disulphide until the filtrate is colorless. The crucible 
and the two tubes are then dried at 225 F. and weighed. The 
filtrate containing the bitumen is evaporated, the bituminous 
residue burned, and the weight of the ash added to that left 
in the two tubes and the Gooch crucible. The sum of these 
weights deducted from the weight of the substance taken 
gives the weight of the bitumen extracted. 

"The practice of some analysts to first extract the bitu- 
men soluble in naphtha or other solvent, and then extract the 
remaining bitumen with carbon disulphide, is not safe with 
some asphalts, as some of the residual bitumen is apt to be 
rendered insoluble, possibly by oxidation while driving out 
the first solvent. 

"Bitumen Soluble in Naphtha. The amount of bitumen 
soluble in naphtha, as has been before explained, is of no 
value excepting as generally indicating within broad limits 
the degree of hardness of an asphalt. The only advantage of 
this test is that it requires no other apparatus than is found 
in every chemical laboratory, and if standard methods could 
be adopted for its use, making a determination for the bro- 
mine absorbed on the naphtha-soluble bitumen and the bitu- 
men insoluble in naphtha, the test might be made of interest 
in the examination of asphalts. The statement often made 



176 SOLID B1TUME\S. 

that an asphalt which contains more than 30 per cent of as- 
phaltene (bitumen insoluble in naphtha) is unsuitable for 
paving is not founded on facts. It does not matter how much 
asphaltene an asphalt contains so long as it can be softened 
into a proper cement by the addition of a suitable flux. I 
have, myself, seen asphalt which contained over 50 per cent 
of asphaltene made into paving cements, and excellent pave- 
ments made therewith. It is also occasionally seen stated 
that the suitability of an asphalt cement for paving can be 
determined by estimating the petrolene which it contains. 
This has been denied by Prof. Peckham, who insists 'that the 
bitumen of Trinidad pitch consists of asphaltene dissolved in 
petrolene, and that its cementitiousness is just as much due 
to one as to the other. Sand cannot be cemented with either 
petrolene or asphaltene alone, neither can wood be cemented 
with either water or glue alone. The cementitiousness de- 
pends upon the amount and quality of the bitumen present/ 
I agree heartily with this remark of Prof. Peckham in all re- 
spects but one, and that is : I would say that an asphalt con- 
sists of asphaltene in a more or less perfect solution of petro- 
lene, as I find that in nearly all cases that while a portion of 
the asphaltene is evidently in solution in the petrolene there 
is another portion that exists in what might be called a col- 
loidal solution. 

"I have adopted the following method for the determina- 
tion of the bitumen soluble in naphtha : A quantity of the as- 
phaltic material sufficient to contain about I gm. of bitumen 
is weighed into a 3~oz. Erlenmeyer flask. This is treated 
with 50 c.c. of naphtha. The flask is then corked and shaken 
several times during the first two or three hours, when it is 
placed away for twenty-four hours. The solution is then 
carefully decanted onto a weighed Gooch crucible with an as- 
bestos filter. This decanting can be done very close, and it 
does not matter if some of the residue does flow into the cru- 
cible. The residue is then treated with consecutive portions 
of naphtha until the filtrate becomes practically colorless. 
The sum of the weights of the residue in the flask and in the 
crucible is deducted from the weight of the substance taken; 
and gives the amount of the bitumen soluble in the naphtha. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 



177 



"As the solvent power of different naphthas varies, it is 
very essential that the same naphtha be used each time for 
making this determination, and it is also necessary to make 
the extraction " at the same temperature each time, as the 
higher the temperature the more solvent action is exerted by 
the naphtha. It is for this reason that I do not advise the use 
of the Soxhlet or other forms of extraction apparatus that use 
return condensers, as it is next to impossible to have the ex- 
tracting solvent at the same temperature for each extraction. 
If the extracting is done by the method which I have de- 
scribed, the naphtha will be of the temperature of the labo- 
ratory, which is usually quite constant. The naphtha which 
I use for extracting distills between 60 and 80 F., and has 
a specific gravity at 60 F., closely approximating 0.680."* 

Mr. Clifford Richardson has given in his "Modern As- 
phalt Pavement," Ed. 1905, the following data under Meth- 
ods of Analysis : 

"Determination of Total Bitumen. One gram of the 
dried or refined material, in a state of very fine p'owder, if 
possible, is weighed out and introduced into a 200 c.c. Erlen- 
meyer flask of Jena glass and covered with about 100 c.c. of 
bisulphide of carbon. It is then set aside for at least five 
hours, or overnight, at the temperature of the laboratory. In 
the meantime a Gooch crucible is prepared with an asbestos 
felt and weighed. This Gooch crucible is of special form, 
with a large filtering surface. It holds 30 c.c., is of 4.4 cm. 
wide at the top, tapering to 3.6 cm. at the bottom and 2.6 cm. 
deep. This is much better for percolation work than the 
usual narrow form of Gooch. The felt is made by beating up 
long-fiber Italian asbestos in a mortar, and suspending the 
finer particles in water and quickly pouring off from the 
coarse particles. Too much of the latter should not be re- 
moved, or the felt will be too dense. The decanted asbestos 
and water can be kept in a bottle for use. To prepare the 
felt the asbestos and water are shaken up and what is found 
to be a proper amount poured into the crucible, which has in 
the meantime been attached to a vacuum filtering-flask by the 
proper connections. As soon as the asbestos has somewhat 

*Proc. Am. Soc. for Testing Materials, III, p. 362, 1903. 



I7 g SOLID BITUMENS. 

settled the vacuum-pump is started and the felt firmly drawn 
on the bottom of the crucible. It is then dried, ignited and 
weighed. 

"After standing a proper time the bisulphide is decanted 
very carefully upon the filter, which is supported in the neck 
of a wide-mouthed flask and allowed to run through without 
pressure. The flask, after being tipped to pour the first por- 
tion, is not again erect, in order to avoid stirring up the 
insoluble material, but is held at an angle on any suitable 
base, such as a clay chimney. After all the bisulphide has 
been decanted more is added, and the insoluble matter shaken 
up with it. This is allowed to settle and decanted as be- 
fore, the insoluble matter being finally brought on the filter 
and washed with the solvent until clean. The excess of bisul- 
phide is allowed to evaporate from the Gooch crucible at the 
temperature of the room. It is then dried for a short time at 
100 C. and weighed. The loss of weight is the percentage of 
bitumen soluble in CS 2 . 

"In the meantime, however, the bisulphide which has 
passed the filter is allowed to subside for twenty-four hours, 
if possible, and is then decanted carefully from the flask in 
which it has been removed, into a weighed platinum or tin- 
weighed porcelain dish. If there is any sediment in this flask 
it must be rinsed back into the Gooch crucible with bisulphide 
and the crucible again washed clean. The solvent in the dish 
is placed in a good draught and lighted. When all the bisul- 
phide has burned the bitumen remaining in the dish is burned 
off over a lamp and the mineral residue, which is too fine to 
subside, is weighed if the burning is done in a platinum dish, 
or dusted out and added to the crucible if in a porcelain one. 
In the former case the weight is added to that of the Gooch 
crucible or substracted from the per cent of bitumen, found 
without its consideration, as a correction. Care must be used 
in this method of procedure that the solvent does not creep 
over the sides of the crucible and that the outside is free from 
bitumen before weighing. In order to avoid this the crucible 
is supported in the neck of a flask with three constrictions, 
the neck extending above the top of the crucible and the latter 
being covered with a watch glass. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 179 

"Mineral Matter or Ash. One gram of the same sample 
material used for the determination of bitumen is weighed out 
in a No. o Royal Berlin porcelain crucible and burned in a 
muffle or over a flame until free from carbon. This must be 
determined by breaking up the cake of ash, moistening with 
water or alcohol, and observing if any black particles of coke 
are present. The weight of the residue is stated as inorganic 
or mineral matter. 

"The determination is, of course, not exact, sulphuric 
acid and the alkalis being volatilized in many cases, but it is 
satisfactory for technical purposes. 

"Organic Matter Insoluble. The amount of this ma- 
terial, sometimes stated as organic matter not bitumen, is 
obtained by difference, that is to say, by subtracting the sum 
of the percentages of bitumen and inorganic matter found, 
from 100. It, of course, includes all of 'the errors in these 
two determinations, and as the error in the bitumen determi- 
nation is one making the percentage too high, and in that of 
the mineral matter too low, the errors are cumulative, do not 
neutralize each other and the percentage of organic matter 
not bitumen is thus always too high. 

"If hot carbon bisulphide, chloroform or spirits of turpen- 
tine are used as the solvent for the bitumen the amount ob- 
tained on extraction is somewhat greater, but in technical 
work the results are no more desirable and such solvents are 
not 'often used, as chloroform is expensive when a large num- 
ber of determinations are carried out and the spirits of tur- 
pentine is so much more viscous, that it filters much less read- 
ily, while the residue of it remaining on the filter must be re- 
moved by naphtha and not by evaporation. 

"The sum of the three determinations, bitumen soluble 
in CS 2 , organic not soluble, and inorganic matter, is therefore, 
always 100 per cent. 

"Naphtha Soluble Bitumen. For the purpose of deter- 
mining the percentage of bitumen soluble in naphtha distil- 
lates, 88 and 62 B. are used. It is extremely important that 
these naphthas should be of the exact degree specified, since 
differences in density will make an appreciable difference in 
the amount of bitumen extracted. The distillate should be 



l8o SOLID BITUMENS. 

that obtained from a paraffine petroleum. The density of 
each lot should be determined with a Westphal balance at 60 
F., and if it is too dense it should be rejected. On the other 
hand, if it is too light, it can be brought to the proper density 
by blowing a current of air through it for a short time, as the 
ordinary temperature in the case of the 88 and after slightly 
warming it in the 62 naphtha. Redistillation of these naph- 
thas is unnecessary, as the products of distillation are no more 
uniform than the original naphtha. 

"It will be found necessary that hard bitumens should be 
reduced to an impalpable powder before attempting to extract 
them, as otherwise the extraction will not be complete. The 
softer bitumens should be divided as much as possible. 

"The bitumen is usually extracted with naphthas of both 
densities in order to determine the difference in their action. 
If the amount extracted by each is the same or nearly the 
same it will point to the fact that the bitumen consists of hard 
asphaltenes mixed with light malthenes, the latter equally sol- 
uble in naphtha of both degrees of density, and but little in- 
termediate hydrocarbons, or of the very hard asphalts fluxed 
artificially with some light oil. If, on the other hand, there 
is a very considerable increase in the percentage dissolved by 
the 62 over the 88 naphtha it may be assumed that the 
malthenes are well graded and natural constituents of the 
bitumen which is being examined. In certain cases, however, 
the use of the two naphthas is unnecessary. It would be use- 
less to extract maltha with a dense naphtha or a glance pitch 
or albertite with a lighter one. * * 

"All determinations are made with cold naphtha by the 
following method : 

"One gram of the substance is weighed into a 200 c.c. 
Erlenmeyer flask, covered with naphtha and allowed to stand, 
as in estimating total bitumen, in fact, the entire process is 
the same with the exception that one or two precautions must 
be observed. It is well not to attempt to break up any lumps 
with a stirring rod, as the substance, especially the softer as- 
phalts, may then adhere to the rod or flask and be difficult to 
detach. It may also be necessary to treat the substance with 
several portions of the solvent instead of two or three, as in 



TECHNICAL ANALYSIS OF SOLID BITUMENS. jgi 

the case of carbon bisulphide. No heat is applied at any time 
in the process. * * * 

"Determination of the Character of Malthenes or Naph- 
tha Soluble Bitumens. The determination of the relative pro- 
portion of saturated and unsaturated hydrocarbons which 
constitute the malthenes is very important in differentiating 
the soluble bitumens. It is made as follows : 

"The 88 naphtha solution of the bitumen under exam- 
ination is made up to a volume of 100 c.c. or reduced to that 
volume by evaporation. It is then placed in a 500 c.c. sep- 
aratory funnel. An equal volume of the solvent naphtha is 
placed in another separatory funnel. The naphtha solution 
and the naphtha are then sbjected to the action of 30 c.c. of 
sulphuric acid of specific gravity 1.84, the acid and naphtha 
being shaken together for exactly three minutes. This is 
most important, since the action of the acid on the hydrocar- 
bons in the bitumen under examination is not a fixed one, but 
will continue more or less indefinitely. After the shaking, the 
acid and the naphtha solution are allowed to stand over night. 
The acid is then carefully drawn off and the shaking again 
repeated with another volume of acid of the same amount. 
This will require a shorter time for the separation of the acid 
and it can be drawn off within a few hours. If the second 
acid is very strongly discolored the acid treatment should be 
continued a third time. In the case of the blank treatment 
with the plain solvent one treatment will be sufficient. The 
naphtha solution and the naphtha are then washed twice with 
water and. afterwards once with a 5 per cent carbonate of 
soda solution, after which one further washing with water 
takes place. The naphtha solution of the bitumen which is 
being treated and the blank naphtha are then poured into 
crystallizing basin 314 ins. in diameter and 2 ins. deep. 
In the plain naphtha is dissolved exactly I grm. of some ex- 
tremely stable petroleum residuum. The two vessels are then 
placed upon the steam-bath to evaporate the naphtha. In or- 
der to avoid creeping the sides of the dishes are imbedded in 
a mass of cotton waste reaching to the top, as creeping is much 
diminished by having the sides of the dish warm. The evap- 
oration is carried on on the steam-bath until the naphtha is 



!8 2 SOLID BITUMENS. 

volatilized and until the blank shows on weighing that the 
residue has returned to its original weight of i gm. It is then 
assumed that the other dish is free from naphtha, and from 
the water which the latter has dissolved in the process of 
washing. This, under the conditions offered in the author's 
laboratory, will require about six hours, but the exposure on 
the water-bath is generally continued one hour after the blank 
has reached a constant weight and further for fifteen minutes 
on an air-bath at 100 C. as control. The results obtained in 
this way are of no absolute value, but are of relative value in 
comparing different fluxes and solid bitumens. It cannot, of 
course, be applied when the bitumen contains an appreciable 
amount of hydrocarbons volatile at 100 C. 

"When 62 naphtha is the solvent its volatilization from 
the residue of bitumen which has been treated is extremely 
difficult, and such a determination is, therefore, not recom- 
mended. 

"In some California residual pitches, which are derived 
from oils containing very -considerable percentages of phenols, 
it may be preferable to treat the 88 naphtha solution with a 
solution of sodic hydrate of 25 per cent strength before the 
treatment with acid in order to remove the phenols. The 
phenols can be separated and identified by neutralizing the 
soda solution with acid. 

Determination of Bitumen Soluble in Carbon Tetra- 
chloride. While in a large majority of cases the same, or 
nearly the same, amount of bitumen is dissolved by carbon 
tetrachloride as by bisulphide of carbon, bitumens are known 
in which hydrocarbons exist which are not as soluble in the 
former solvent for example, one of the Venezuelan asphalts 
when overheated in refining, grahamite and some of the re- 
sidual pitches. The use of the solvent may, therefore, be 
desirable at times for the purpose of differentiating the native 
bitumens. It is used cold in exactly the same way as carbon 
bisulphide. In the case of the grahamites, hot carbon tetra- 
chloride dissolves an appreciable amount after the cold sol- 
vent has ceased to act. The residue on the Gooch crucible 
may, in this case, be removed to an Erlenmeyer flask and 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 183 

treated further with the solvent. A definite result is more 
satisfactorily obtained with the cold solvent." 

The numerous methods of analysis that have been de- 
scribed under this section are all modifications of one general 
process of separation of constituent principles that exist in 
solid bitumens, in relation to which chemists have assumed to 
know a great deal but really know very little. As a subject 
of chemical investigation a solid bitumen may properly be 
compared with a drug, which consists of a very complex mix- 
ture of organic compounds like opium, for example. No 
pharmaceutical chemist would think of analyzing such a drug 
by subjecting it to distillation, which would almost certainly 
be destructive. The method employed would be one of perco- 
lation by solvents, resulting in a series of solutions which 
would be examined separately, yielding by elimination and 
exclusion, purified products that would in the end determine 
of what the mixture consisted in the beginning. 

Boussingault's procedure was based on methods of proxi- 
mate analysis that are not now applied to such problems. His 
somewhat fanciful names were based on wrong views con- 
cerning the composition of bitumens, that, by adoption into 
the nomenclature of recent years, under changed conditions, 
have 'only led to confusion. I think a perusal of the preceding 
pages fully demonstrates the truth of this statement. 

The suggestion of Dr. S. P. Sadtler that solvents of fixed 
purity be employed in the analysis of solid bitumens is wholly 
sound. It is extremely unfortunate that a liquid so variable 
in composition and qualities as so-called petroleum ether or 
naphtha, should have been selected as a solvent for that por- 
tion of solid bitumens that is supposed to determine their 
quality for paving and other technical purposes. 

This liquid is produced in different parts of the world, 
from such varied crude materials and under such varied con- 
ditions, as to be impossible of uniform qualities and chemical 
composition, even when possessing uniform physical proper- 
ties such as are determined by specific gravity, boiling point, 
etc. I repeat that it is extremely unfortunate that a fluid of 
such uncertain properties should have been selected to answer 
the requirements of such a critical purpose. 



1 84 SOLID BITUMENS. 

If, however, those persons to whom the above consider- 
ations do not adequately appeal, continue to insist that petro- 
leum ether shall be used in the analysis of solid bitumens, it 
should also be insisted that the volatile product of the petro- 
leum refineries that is most constant in its composition and 
properties be carefully used, and not the heterogeneous dis- 
tillates, the identity of which are supposed to be determined 
mainly through identity of specific gravity and other physical 
properties, that really determine little or nothing in regard 
to the composition and other chemical properties on which 
its chemical action depends. 

My purpose, therefore, in writing the pages that follow 
is not alone to present a scheme, the use of which has been 
confirmed, by many years' experience to be, for all purposes, 
superior to any other, but, also to promote so far as my in- 
fluence may promote, the use of solvents of fixed purity to 
the exclusion of any variety of naphtha or petroleum distil- 
lates of any kind. 

The object of the technical analysis of solid bituminous 
minerals is not to determine the ultimate chemical composition 
of any of the complex compounds that may be mixed together 
to form the material under consideration, hence the method 
employed is more or less empirical. 

The determination of the amount of whatever solubles 
may be selected gives results at the same time both abso- 
lute and relative. These results are of little value when taken 
singly and alone. They were suggested originally by an at- 
tempt to imitate the process described in Allen's "Commer- 
cial Organic Analysis," and it was for some time supposed 
by Miss Linton, myself, and probably by others, that a sim- 
ilarity existed in the materials dissolved by these same men- 
strua from different varieties of bitumen. I have some time 
since reached a conclusion that this is not the case. 

In 1892 I distilled, under pressure, some California pe- 
troleum, and obtained a "cracked" distillate. I removed from 
this distillate the lighter portion and placed the residue re- 
maining in the retort in a Becker glass, where a solid material 
gradually accumulated in a ring just below the surface of the 
liquid, and an addition of petroleum ether to the liquid pro- 



TECHNICAL ANALYSIS OF SOLID BITUMENS. ,85 

duced a brown precipitate resembling ferric oxide when pre- 
cipitated from its solutions. A precipitate having the same 
appearance can be thrown down from a turpentine, chloro- 
form, or benzol solution of Trinidad pitch. I, for a long time, 
supposed they were the same substance asphaltene but 
they are entirely unlike. What relation, if any, the}- may 
bear to each other has not yet been determined. The precipi- 
tate from the California distillate appears to be wholly or- 
ganic; that from the turpentine solution of Trinidad pitch 
appears to consist largely of a compound of alumina; while 
that from the chloroform soluble of the same bitumen ap- 
pears to be an organic salt of iron. Technically these solu- 
tions, with their precipitates, bring into consideration certain 
problems concerning solid bituminous minerals of the highest 
importance. The result of an analysis that sets forth the 
specific gravity, melting point, flowing test, petroleum ether, 
and carbon disulphide solubles, with perhaps the total amount 
of nitrogen and sulphur, tells very little concerning the ap- 
plication to any particular purpose of any given specimen of 
bitumen. The term "organic matter not bitumen" is mislead- 
ing, for in many cases the volatile matter so determined is 
not organic at all. 

That which is of primary importance in the analysis of 
an asphaltic mineral is to learn what proportion of the min- 
eral consists of hydrocarbons, soluble in solvents that will 
separate and distinguish them. If the volatile and combusti- 
ble matter that appears as "organic matter not bitumen" is 
large in amount, it is of scarcely less importance to know 
exactly of what this material consists. Next in importance is 
the total amount and manner of combination of the sulphur; 
next the total amount and manner of combination of the 
nitrogen ; and lastly, the total amount and manner of com- 
bination of the iron and alumina. The amounts of silica, 
lime, and magnesia should be known as guides in preparing 
the street mixtures, but they are of no significance in the 
determination of the specific qualities of the bitumen. 

The method of analysis as described in Miss Linton's 
papers was the germ from which has been evolved by various 
modifications made by Miss Linton, my son, Dr. H. E. Peck- 



1 86 



SOLID BITUMENS. 



ham, and myself, the following' described apparatus and 
method of procedure, which has been tested in my laboratory 
by several years' constant and very successful use. 

An ordinary retort stand is selected with a rod about 
24 in. high. (Fig. 2.) A piece of brass tubing 10 in. in length, 




Fig. 2. Apparatus for Determination of Solid Bitumens. 

with an external diameter of ij/j in. and an internal diameter 
that will closely fit the rod, is soldered into a brass disk at 
either end 16 in. in diameter and % in. thick. One of these disks 
is entire, the other contains 8 circular orifices equidistant 
from each other, the centers of which are 2^4 in- from the 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 187 

circumference of the disk. The orifices are 2^2 in. in diame- 
ter, and are numbered I to VIII. The disks, with the orifices 
uppermost, are placed with the tube enclosing the rod so 
that they will rotate upon the rod at right angles with it. 

Eight 200 c. cm. Erlenmeyer flasks are washed, dried, 
and weighed. They are then numbered i to 8, which with their 
respective weights are marked upon them with a diamond. 
These are placed beneath the corresponding numbered ori- 
fices in the upper disk. A second set of eight flasks is 
weighed, numbered and marked. In each of the orfices in 
the upper disk is placed a 2^5 in. Bunsen funnel, into the 
neck of which has been fused a glass stopcock of the best 
quality. The necks of the funnels below the stopcock should 
be ground at a bevel and should enter the flask about an inch. 
The funnels should be covered each with a 4 in. watch glass. 
With this apparatus four determinations can be made in 
duplicate at the same time. 

The following groups of solvents may be used: 

Either bisulphide of carbon, chloroform or benzole alone 
may be used to determine the total amount of bitumen, or 

Petroleum ether, and bisulphide of carbon; 

Petroleum ether, and chloroform ; 

Petroleum ether, boiling spirits of turpentine and either 
bisulphide of carbon or chloroform. 

Distilled water followed by 95 per cent methyl alcohol, 
ethyl ether and chloroform. 

Distilled water followed by acetone, ethyl ether and 
chloroform. Each of these combinations of solvents if used 
on a series of bitumens tells its own story and furnishes its 
own data by which to distinguish the members of any series 
from each other. I have used all of them and each is to be 
recommended for special purposes and occasions. 

Bisulphide of carbon is cheap, expeditious, disagreeable 
and very inflammable. 

Chloroform is expensive, agreeable and non-inflammable. 
Moreover, it is a more certain and complete universal sol- 
vent for all classes of bitumens than any other liquid. 

Boiling spirits of turpentine determines the group rela- 
tions of many bitumens with great exactness and has been 



1 88 SOLID BITUMENS. 

found by the author, ever since Miss Linton first proposed 
its use, to give frequent and valuable testimony in the an- 
alysis of bitumens, but, the objections urged against its use 
by Dr. Sadtler and others are admitted to be sound. Never- 
theless, the group petroleum ether, followed by boiling spirits 
of turpentine, followed after washing by chloroform, is a 
group that experience is likely to retain for occasional use. 

I have elsewhere* shown that acetone does not furnish 
results that are comparable with those furnished by petro- 
leum ether. I am, however, convinced that the scientific in- 
vestigation of bitumens would make much more rapid prog- 
ress if Dr. Sadtler's suggestion that solvents of fixed purity 
should be universally adopted in all researches on solid bitu- 
mens even at a cost of time and money and the establishment 
of a new series of constants. For, chemists have got to build 
on a more solid foundation than assumptions and probabili- 
ties, and the generalties expressed in the general classifica- 
tions of saturated and unsaturated compounds before any 
strictly scientific knowledge will be gained concerning the 
composition of bitumens. 

Acetone is more nearly allied to the alcohols than to 
the pure hydrocarbons, and therefore dissolves substances 
that are wholly insoluble in hydrocarbons. In illustration, 
two samples of Trinidad pitch. No. I, a sample of crude 
pitch. No. 2 a sample of Epuree, made on the island, were 
analyzed by the use of petroleum ether and acetone with the 

following results : 

No. 1. 

Petroleum ether soluble 33.736 ) 

Boiling spirits turpentine soluble... 10.511 f 52.367 total bitumen. 

Chloroform soluble 8.120 ) 

Organic matter not bitumen. ...... 10.851 j. 47.580 non-bituminous ma- 
Inorganic matter 36.729 f terial. 

99.937 per cent. 
No. 1. 

Acetone soluble 28.180 ) 55 Ig5 j bitumen 

Chloroform soluble 27.005 \ 

Organic matter not bitumen 9.835 j. 44.815 non-bituminous ma- 
Inorganic matter 34.980 f terial. 

100.000 per cent. 



*Jour. Franklin Institute, March, 1896. 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 189 

No. 2. 

Petroleum ether soluble 33.625 ) 

Boiling spirits turpentine soluble.... 15.575 > 51.875 total bitumen. 
Chloroform soluble 2.675 ) 

Organic matter not bitumen 10.150 j. 48.125 non-bituminous ma- 
Inorganic matter 37.975 \ terial. 

100.000 per cent. 

No. 2. 

Acetone soluble 26.310 ) AQ * * i u-* 

Chloroform soluble 29.170 f 55 ' 48 total bltumen - 

Organic matter not bitumen 9.600 I 44.52 non-bituminous mat- 
Inorganic matter 34.920 ) ter. 

100.000 per cent. 
No. 1. No. 2. 

Petroleum Ace- Petroleum Ace- 
Ether, tone. Ether. tone. 

Total bitumen 52.367 55.185 51.875 55.480 

Non-bitumen 47.580 44.815 48.125 44.520 

To still further test the relation of the two solvents, 
equal portions of a very dry Egyptian asphaltum were ex- 
hausted under identical conditions with petroleum ether and 
acetone. The results are given below: , 

Per cent. 

Petroleum ether soluble 38.03 

Acetone soluble 8.68 

Also, an Athabasca River maltha was exhausted in the 
; ame manner, with the following results: 

Per cent. 

Petroleum ether soluble 73.863 

Acetone soluble 24.333 

No difference was observed between the solvent power 
of cold and boiling acetone in either case. The dry Egyptian 
asphalt and the semi-fluid maltha exhibit the extremes to 
which any solvent of bitumen is likely to be applied, and the 
lack of parallelism is enormously large in both cases. 

After several years' experience I am satisfied that the 
simplest as well as most satisfactory method of procedure is 
as follows: The solvents should be freed from water. The 
petroleum ether and chloroform should be agitated with 
strong sulphuric acid and distilled over caustic lime, or dry 



190 



SOLID BITUMENS. 



sodium carbonate, with steam. The turpentine should be 
shaken with freshly burned lime, poured off, and rapidly dis- 
tilled. A rapid method which removes the water but does 
not otherwise purify these liquids, consists in thorough agita- 
tion with dry powdered plaster of Paris. Apparently all of 
these liquids are sold with all of the water they will hold. 

The niters that I use are those prepared by Baker and 
Adamson, n cm. in diameter, which have been washed with 
both hydrochloric and hydrofluoric acids. These niters are 
not appreciably affected by the solvents. Three of them are 
balanced, and two are placed in separatory funnels, into which 
are weighed such portions of the bituminous mineral as will 
assure about half a gram of bitumen. The filter is filled with 
petroleum ether, which is allowed to run through slowly until 
the color has perceptibly diminished, and then the stopcock is 
closed between each addition of solvent for 15 to 30 minutes, 
until the solvent passes colorless. It is well to leave the. fun- 
nels to stand over night at the end, but not at the beginning 
of the operation. All three filters are dried in the air, then 
in an oven, at about 150 F., and weighed. Very close work 
can be ! done in this way. The solution may be tested with 
fuming nitric acid, or may be evaporated, and the residue 
treated with nitro-sulphuric acid, or 10 per cent sulphuric 
acid for basic oils. The dried filters are returned to the fun- 
nels and exhausted as rapidly as possible with boiling spirits 
of turpentine. The turpentine should not be allowed to cool 
in the filters. When the exhaustion is complete the filters are 
washed with petroleum ether by filling the closed funnel 
above the filter to complete submergence and allowing the 
filter to digest for 30 minutes. A second digestion will usually 
completely remove the turpentine. The filters are then dried 
and weighed. The turpentine solution may be diluted with 
several times its volume of petroleum ether and the precipi- 
tate examined by treatment with nitric acid, etc. 

The dried filters are again returned to the funnels and 
after being exhausted with chloroform are again dried and 
weighed. The chloroform may be distilled off and the resi- 
due washed in petroleum ether and tested. 



TECHNICAL ANALYSIS Ol< SOLID BITUMENS. 191 

The dried filters are again returned to the funnels wetted 
with alcohol, and after exhaustion with 10 per cent hydro- 
chloric acid, are washed, dried, and weighed. The loss is 
calcium and magnesium carbonate and calcium sulphate, if 
any is present. The calcium, magnesium, and sulphuric acid 
may be determined in the acid solution if desired, also iron 
and alumina, if any are present. 

The filters are cut in small pieces and deflagrated with 
sodium carbonate and potassium nitrate, and sulphur, as 
pyrites, silica, iron and alumina, are determined in the fused 
mass. 

A new portion of the bituminous mineral, containing at 
least l / 2 gm. of bitumen is deflagrated with sodium carbonate 
and potassium nitrate, and in the solution of the fused mass 
silica, sulphur, iron, and alumina may be determined, or lime 
and magnesia, if they are present. 

Nitrogen may be determined by any method desired. A 
portion is dissolved in pure chloroform and the solution 
washed with 10 per cent dilute sulphuric acid. The acid solu- 
tion is neutralized with sodium hydrate, when nitrogenous 
basic oils will be recognized by their odor. Another portion 
is exhausted with chloroform and the residue extracted with 
ammonium hydrate for the peat, or other organic acids. 

Free sulphur will be found in the petroleum ether solu- 
tion. Organic compounds of alumina will be chiefly found in 
the turpentine solution. Very few natural, solid bitumens 
are free from at least a trace of these curious and little-known 
substances. 

"Organic matter not bitumen" consists of coke, peat 
acids and humus, partially decayed woody fiber and sulphur. 
If the bitumen contains ferrous sulphate or pyrite, the sul- 
phuric acid or sulpur will be lost here and the iron will ap- 
pear in the residue saturating the filter ash as colchotha, as is 
not infrequently observed.* 

Another method of procedure, that requires more time, 
but which gives more satisfactory results is as follows : 

From 0.5 gms. to 5.0 gms. of the samples are weighed in 
duplicate 'into the second numbered series of Erlenmeyer 



'Jour. Soc. Chem. Ind., xvi, May, 1897; xvii, May, 1898. 



192 SOLID BITUMEXS. 

flasks, the numbers corresponding to the numbered funnels 
and receiving flasks. Fifty c. c. of petroleum ether or acetone 
is poured into the flasks which are closed with a good cork 
and set aside with occasional shaking, preferably over night. 
The sample should not be pulverized, as pulverizing would 
destroy, in the residue, materials that distinguish some of the 
bitumens. The use of a Gooch crucible has the same result, 
destroying organic forms and changing mineral constituents 
of residues, that are characteristic of some of the bitumens. 

When the fragments of bitumens are broken down the con- 
tents of the flask are decanted upon the filter in the corre- 
sponding numbered funnel. Other portions of the solvent 
are added to the flask in small portions, successively, and 
after agitation and subsidence, are decanted upon the filter. 
This is repeated until the filtrate passes colorless. The flask 
containing the filtrate is allowed to rest from 12 to 48 hours, 
when the liquid is carefully decanted into another flask and 
preserved for further examination. The flasks and filters are 
air dried, then dried "at 220 F. and weighed, after cooling, in 
the air of the laboratory. 

Experiments made during many years have proved that 
the fine residue that settles from the above filtrate is as varied 
in composition as the bituminous materials under examina- 
tion. It is seldom or never wholly a mineral residue, but 
usually, especially in the case of crude natural bitumens, it 
consists of organic salts that can be dissolved in suitable sol- 
vents forming transparent solutions, from which they can be 
precipitated as amorphous solids. Such reactions are not 
characteristic of a suspended solid, no matter how finely di- 
vided it may be nor how long it may take to subside. 

The weighed filters are returned to their respective fun- 
nels. Pure doubly refined spirits of turpentine is poured upon 
the residue in the flask last decanted, and boiled. While boil- 
ing the flask is rinsed and the hot solution is poured into the 
flask containing the bulk of the residue. The turpentine is 
again brought to a boil, allowed to subside a moment and 
poured through its numbered filter into the first flask. In 
this way the residue in both flasks and the funnel is brought 
under the action of the boiling turpentine, which will com- 



TECHNICAL ANALYSIS OF SOLID BITUMENS. 193 

pletely dissolve many natural bitumens and most residuums. 
The two flasks and the filter are washed with petroleum ether 
until the turpentine is completely removed, when they are 
again dried and weighed. 

The residues in the flasks are treated with pure chloro- 
form and thq solvent passed through the filter. The filter 
and flasks are dried and weighed. 

The sum of the amounts dissolved in the different f.ets of 
solvents represents the total amount of bitumen present. 

In residual pitches the residue remaining may consist of 
nothing but coke. In natural bitumens it consists of much 
or little of a variety of substances. The filter may be mois- 
tened with alcohol which may be allowed to percolate into 
one of the flasks and after moistening the interior thereof, the 
liquid may be poured into the other flask. If this precaution 
is not taken, the next solvent used, consisting of dilute hydro- 
chloric acid (i 9) will be repelled from the surfaces without 
wetting them. This dilute hydrochloric acid will decompose 
all of the carbonates present, but it will leave the silica, clay 
and pyrite untouched. The organic matter not bitumen will 
also be undissolved. The residue remaining should be thor- 
oughly washed with distilled water and carefully air dried. 
The dried material should then be carefully examined under 
a microscope of low and high power. There will be recognized : 

The wing cases of insects. 

Fragments of vegetation, including partially decayed 
wood. 

Clay. 

Fragments of crystals of quartz. 

Grains of quartz of various forms. 

Pyrite, in grains or crystals, some of them very minute. 

Other organic or mineral forms rarely occur. 

I fully agree with Mr. Dow in his judgment respecting 
the use 'of different forms of the Soxhlet apparatus. This 
apparatus in several forms, suggested by experience, was 
given a very thorough and prolonged trial in our laboratory 
and given up as impracticable not only for the reasons given 
by Mr. Dow, but also for the form of the filter, the unavoid- 
able spattering of the contents and the generally difficult 
manipulation which it inevitably required. 



194 SOLID BITUMEXS. 

I have gone back to my filters and separating funnels 
and normal temperature of the laboratory, from every at- 
tempt to use the Soxhlet apparatus, the Gooch crucible or 
Mr. Dow's test tubes. No apparatus or method of analysis 
by percolation fulfils all of the requirements suggested by 
theoretical considerations, nor is any apparatus or method 
free from criticism. The selection depends upon a maximum 
of information respecting the specimen under examination 
obtained for the least expenditure of time, reagents, risk of 
fire and other accidents, with a minimum of sources of error. 
Without denying any of the claims made for other methods, 
I have found the method contrived by Miss Linton to fulfill 
the above named requirements best. 

Concerning solvents, I have used all that have been sug- 
gested. I think before any really scientific knowledge is 
gained concerning the chemistry of bitumens, chemists will 
have to abandon the wholly empirical methods of analysis 
based upon the use of petroleum distillates and carbon bisul- 
phide and take up in earnest the tedious, but fruitful, meth- 
ods requiring the use of solvents of fixed purity, suggested by 
Dr. S. P. Sadtler. These liquids are alcohols, of not less than 
95 per cent purity, acetone, commercially pure, ethyl ether 
and chloroform. Carbon tetrachloride may perhaps be added 
to this list. I am confident that with these solvents natural 
bitumens will eventually be separated by constant reactions 
from residual pitches and both classes of substances will be 
separated into their constituent compounds of fixed composi- 
tion, which through their substitution compounds will be re- 
ferred to their proper places and relations with systematic 
names, not fanciful names, based upon assumptions and prob- 
abilities, often misleading, and never final. 

I have made use, with increasing frequency, of commer- 
cially pure acetone, in all varieties of investigations of bitu- 
minous materials. Its composition is practically constant. 
Its reactions are equally so. Its reaction upon coal tar 
pitches are very characteristic. It is of the highest efficiency 
in the separation of natural bitumens. In the investigation of 
wood paving blocks, saturated with mixtures of which gen- 
uine creosote oil forms a part, it is unequaled. While it is 
very volatile, it is not so extremely volatile as the petroleum 



TECHNICAL ANALYSIS OF SOLID BITUM1LXS. 



195 



distillates of high specific gravity, which it is designed to dis- 
place. Boiling at 80 C. it is easily expelled from the residues 
it dissolves. Followed by ether and chloroform or ether 
alone, the three solvents appear to really analyze bitumens 
and not to separate them into empirical mixtures as complex 
as the original substance. Moreover, it is innocuous to the 
operator. 

With this admittedly inconclusive discussion I leave a 
subject that is becoming, I believe, one of the most fruitful 
fields of chemical research, presented to the chemists of this 
opening century. 



CHAPTER XIII. 

SPECIAL CHEMICAL AND PHYSICAL METHODS OF 

ANALYSIS BY WHICH SOLID BITUMENS MAY 

BE RECOGNIZED AND DISTINGUISHED. 

FIXED CARBON. 

The estimation of fixed carbon by the following described 
method, is found to furnish data that are of value in the de- 
termination of the different varieties of solid natural bitumens, 
and their separation from each other and from residual 
pitches and other forms of "Factice." The method of de- 
termination is as follows : 

Place one gram of the bitumen in a platinum crucible 
holding 30 c. c. and with a tightly fitting cover. Heat over 
the flame of a Bunsen burner for five minutes. Some opera- 
tors recommend seven minutes, but I have found five minutes 
to be ample. The volatile matter burns off in from one to 
two minutes. The crucible should be supported on a plati- 
num triangle so far above the top of the burner as to bring 
the bottom of the crucible 6 cm. above it. The flame should 
burn free about 20 cm. high, and the crucible should be thrust 
into it in such manner as to immediately receive the full 
effects of it. The upper surface of the cover and the sides 
of the crucible will immediately burn clear, but the under sur- 
face of the cover and the inside of the crucible will remain 
covered with a thin film of carbon. The flame should burn 
free from draughts. 

The crucible and cover are weighed and the loss com- 
puted as "volatile matter." 

The carbon is then burned off the cover and the crucible 
is again placed in the flame and the combustible matter fully 
burned off, leaving nothing in the crucible but the clean ash. 
After weighing, the second loss is computed as "fixed car- 
bon." 

Both these constants are very certain in a given speci- 
men, and may be duplicated with great accuracy. They are 

196 



SPECIAL CHEMICAL AND PHYSICAL METHODS. 197 

wholly empirical data closely resembling the volatile and 
fixed carbon of coal but with the ash they furnish a valuable 
means of identification and separation. 

The natural bitumens are usually high in ash and fixed 
carbon. The specimens of "Factice" are nearly or quite free 
from ash and low in fixed carbon. 

The bituminous rocks form a class by themselves. The 
bituminous lime and magnesian rocks cannot be burned for 
fixed carbon, as the carbonic acid present in the rock is added 
wholly or in part to the volatile combustible matter. In the 
case of rocks containing carbonates, the bitumens should be 
dissolved from the mineral matter in chloroform, the solution 
evaporated at a low temperature and the bitumen then 
treated as if it were an original specimen. 

STREET MIXTURES AND SURFACES. 

Street mixtures should never be pulverized. They 
should be rubbed in an iron mortar only sufficiently to pre- 
pare an average sample. Street mixtures of good quality are 
pulverized with great difficulty. The poorer ones may be 
easily reduced to a powder but little if any finer than the 
sand used. If the sand is reduced to a fine powder many 
characteristics that serve to identify the bitumen will be de- 
stroyed. Five grams of the prepared sample are weighed into 
duplicate, balanced filters and exhausted with chloroform or 
bisulphide of carbon. If any of the finely divided mineral 
aggregate passes the filter, the filtrate should be allowed to 
stand at rest at least twelve hours, or over night, when the 
liquid is decanted from the matter that has subsided, the sub- 
sided matter washed with a fresh portion of the solvent, the 
flask dried, wiped clean and weighed. The weight marked on 
the flask is substracted from the total weight and the differ- 
ence added to that of the residue remaining in the filter. The 
sum of the weight of the residues remaining in the two filters 
substracted from 10 gms. gives the mean percentage of the 
bitumen found in the two duplicate samples. 

The residues when moistened with alcohol, treated with 
dilute (i 9) hydrochloric acid, washed with distilled water 
dried and weighed, show a loss which represents the percentage 
of carbonates in the asphaltic mixture. Besides the carbon- 



KjS SO Lin BITUMRXS. 

ates, there may be a small and varying percentage of matter 
dissolved from pulverized trap-rock or other rocks which 
form a part of the mineral aggregate used. For technical pur- 
poses, this error, while it is recognized, may be disregarded. 

The washed and dried residue should be carefully ex- 
amined under a microscope, and then burned, if such treat- 
ment is desired. 

Surfaces that have been laid should be carefully sepa- 
rated from any binder that mav adhere to the specimen, or 
any pieces of rock or gravel that may have been pressed into 
them. The surface should then be treated precisely as if it 
were a mixture. 

Surfaces that have been laid for some months or years 
will be found to vary in total bitumen from the surface down- 
ward. 

It will be often found advisable to use the three-solvent 
method in the examination of mixtures and surfaces. 

Great differences will be observed in the action of sol- 
vents upon mixtures and surfaces containing different kinds 
of bitumens. Trinidad pitch and mixtures containing it, 
forms, with all solvents, a more or less viscous solution that 
filters slowly, leaving the filter stained with peculiar black 
markings that are readily distinguished when once observed. 
Other bitumens filter more readily, leaving the filters dis- 
colored in their own peculiar manner, that may be readily 
recognized. Residual pitches from coal tar are not readily 
soluble in petroleum ether, but dissolve in acetone, forming 
an opalescent solution of a pale amber color. These pitches 
usually leave a filter discolored with finely divided coke. 
Residual pitches from petroleum are acted on by solvents 
very readily and leave a filter nearly as clean as at the begin- 
ning. Experience soon teaches the operator with Miss Lin- 
ton's filters to recognize a large number of data difficult to 
describe but furnishing very constant characteristics from 
which the kind of bitumen may be distinguished. 

FUMING SULPHURIC ACID TEST. 

(Malo Durand-Claye Meinecke.) 

According to Leon Malo, the following, originally pro- 
posed by Durand-Claye, serves in the laboratory of the "Ecole 



SPECIAL CI1KMICAL AND PHYSICAL METHODS. 199 

des Ponts et Chausses," in Paris, to distinguish the difference 
between natural and artificial asphalts. The substance under 
examination (most likely a specimen of either stamped or 
molded asphalt) will after separation of the mineral constitu- 
ents by extraction with carbon bisulphide and the evapora- 
tion of the solution to a residue, be dried by careful 
warming until it becomes firm and brittle. It is then pul- 
verized. In a test tube upon o.i gm. is poured 5 c. cm. of 
fuming sulphuric acid at 66 B. The specimen is left to stand 
for 24 hours and is then slowly diluted, from a pipette with 
10 c. c. of water, avoiding an excess of heat. It is then 
brought upon a filter and washed with sufficient water to 
make 100 c. cm. The filtrate from pure natural bitumen is 
colorless or at most slightly colored ; that from coal tar pitch 
is dark brown inclining to black. 

C. Meinecke shakes o.i gm. of the ash-free asphalt with 
10 c. cm. of fuming sulphuric acid (strong) which reveals 
remarkable differences, especially in a thin stratum, also by 
lowering and raising the test tube, that it may flow back- 
slowly on the interior surface. As the liquid flows back, it 
is, in the case of: 

(1) American asphalt, brown running into gray. 

(2) Syrian asphalt, brown. 

(3) Trinidad asphalt, brown. 

(4) Brown-coal tar pitch, gray inclining to brown. 

(5) Coal tar pitch, gray black, trace of greenish, streaky 
(from particles of coal). 

From this it may appear that the natural asphalts give 
brown, and the artificial, gray mixtures. 

Meinecke remarks further, that in these mixtures of sul- 
phuric acid after standing 24 hours and being tested by the 
microscope, more or less coking can be observed in the differ- 
ent asphalts. Coal tar pitch is sharply different from the as- 
phalts through the intensive blackness due to the proportion- 
ately large particles of carbon, of nearly the same dimensions, 
that are arranged in planes. The asphalts of Syria, Trini- 
dad and America, as well as brown-coal tar pitch, show sim- 
ilar particles, so that a difference in this way is scarcely pos- 
sible to determine. 



200 SOLJ/> H/T('MIL\S. 

The reaction of Durand-Claye in the manner set forth in 
the above mentioned sulphuric acid mixture poured with 
shaking into between 15 and 20 c. c. of water and filled up 
to 100 c. c. gives, when filtered and poured into a test tube 
i8mm. wide, according to Meinecke, the following results: 

(1) American asphalt, pale yellow-brown solution. 

(2) Syrian asphalt, yellow-brown, clearer than No. I. 

(3) Trinidad asphalt, yellow-brown, clearer than sherry. 

(4) Brown-coal tar pitch, dark brown ; it does not per- 
mit itself to be read through. 

(5) Coal-tar pitch, black, opaque. 

To prove the presence of coal tar asphalt in natural as- 
phalt, Leon Malo uses the Durand-Claye reaction to ap- 
proach by a colormetric way a determination of the sophisti- 
cation of the mass, as samples of natural asphalt mingled 
with different percentages of coal-tar pitch impart for each 
percentage a certain intensity of color to the aqueous filtrate.* 

ALCOHOL AND ALCOHOL-BENZINE TESTS. 

Hauenschild. 

The proof of coal-tar pitch in natural asphalt succeeds, ac- 
cording to Hauenschild, most easily, when i gm. of the mate- 
rial is heated to 200, then, after cooling, pulverized and im- 
mersed in about 5 c. c. absolute alcohol. After standing in a 
test tube a short time, the content of coal-tar pitch is shown 
through the yellowish color of the alcohol with a slightly 
green-blue fluorescence, in which with an increasing propor- 
tion of pitch, the dark yellow is changed into the yellow- 
green fluorescence. 

A more general method even than that of Durand-Claye 
is found in the different behavior of natural and artificial bitu- 
mens with benzine and alcohol. Upon i gm. of the pulverized 
product is poured 5 gms. of rectified benzine in a closed glass 
vessel and shaken until the solution appears deep black. The 
solution is filtered and five or six drops of the filtrate are 
dropped into a test tube containing 5 c. c. benzine and an 
equal amount of strong ethyl alcohol. After vigorous shak- 
ing the solution is left at rest, when there will appear an 
upper benzine layer separated from a lower alcohol layer. 

*Ann. des Fonts et ChaussSes, 1879, vol. 2. 



SPECIAL CHEMICAL AND PHYSICAL METHODS. 2OI 

It is then subjected to successive benzine-alcohol treatments. 
The coloring of the third solution discloses whether the nat- 
ural asphalt has been falsified with coal-tar pitch. If it is 
colorless or only slightly yellow, then the asphalt is pure ; if 
it shows a golden brown coloring, then it contains coal-tar 
pitch. 

Mixtures of bitumen and pitch show mezzotints ; in this 
colormetric way, a proportion of from 10 to 20 per cent of 
coal-tar pitch can be proved to be present.* 

PRECIPITATION METHOD. 

Kovacs and Sotet. 

According to J. Kovacs it is impossible to determine 
quantitatively the falsification of an asphalt by petroleum 
residuum in less proportion thai> 20 to 25 per cent, but the 
presence of an additional quantity can be proved by the fol- 
lowing, communicated and worked out in association with 
S. Sotet. 

A sample of the asphalt to be examined is treated with 
carbon disulphide and the filtered extract evaporated to a dry 
residue at 110 C. The dried residue is dissolved in two and 
one-half times its weight of carbon disulphide, and at the 
same time an equal concentrated solution of pure asphalt in 
carbon disulphide is placed beside it. 

One c. c. of the solution is poured into 2 l / 2 c. c. of oil of 
turpentine in a test tube. If the product contains coal-tar 
pitch, a light brown solution and a light brown precipitate is 
obtained, while the solution of natural asphalt remains dark 
colored and gives no precipitate. 

The original solution is treated with absolute alcohol in 
the proportion of i 10, when the coal-tar pitch appears as 
a brown precipitate ; natural asphalt furnishing a black, sticky 
pitchlike precipitate, while petroleum pitch furnishes a fine, 
black, flocculent precipitate. If the precipitate is filtered off 
and dried at 90 to 95 C. that from coal-tar pitch is like flour, 
is dull and of a light brown color, while that from natural 
asphalt is black, sticky, brilliant and when warmed can be 
drawn out into fine threads. Under the same conditions, pe- 

*See E. Dietrich, Die Asphaltstraszen, p. 44; Durand-ClayS, Nothling, 
Der Asphalt, p. 35. 



JOJ SOLID B1TUMEXS. 

troleum residuum gives a precipitate black, dull, earthy and 
easily broken between the fingers. 

One c. c. of the original solution, shaken with 5 c. c. of 
absolute alcohol, furnishes with coal-tar pitch a brown pre- 
cipitate and a black pitch like scum, petroleum pitch a black, 
muddy precipitate, whilst pure asphalt gives a black pre- 
cipitate or pitchlike coherent scum. The supernatant fluid 
above the precipitates is reddish brown with petroleum pitch, 
and light brown with coal-tar pitch and pure asphalt. 

The filter paper spread out and dried at 90 to 95 C., 
shows precipitated upon it, with coal-tar pitch and asphalt, 
glistening, pitchlike material, sticky and adhesive after warm- 
ing; while petroleum pitch on the contrary, yields a muddy, 
friable mass leaving behind transparent, oily, red-brown spots 
upon the paper.* 

The cohesive properties of the bitumens obtained from 
natural asphalts and solid bitumens explain the superior qual- 
ities exhibited by these materials when used for paving and 
other purposes, when compared with the various forms of 
factice produced by artificial methods. 

DETERMINATION OF PARAFFINS. 

Kramer and Spilker. 

Of the component constituents of natural asphalt, there 
is only a single one paraffine that has been separated in 
a condition of purity. For the determination of the same, I 
describe a method which Kramer and Spilker have given for 
the determination of parafHne in raw anthracene as follows: 

Ten gms. of the bitumen, very finely pulverized, are 
mixed in a 100 c. c. graduated cylinder with 70 c. c. of ether, 
agitated for some time, filled up to the mark with ether and 
set aside. Fifty c. c. of the clear solution is brought by means 
of a pipette into a porcelain dish, left until the ether evapo- 
rates and the residue dried for half an hour at about 100 C. 
The cooled residue is then made as fine as possible in the 
dish and 8 c. c. fuming sulphuric acid, added, the whole being 
well mixed and heated, in the dish for two hours with fre- 
quent stirring at about 100 C. The contents of the dish are 

Chem. Rev. d. Fett u. Harz-Iml., 1900, p. 8; 1902, p. 1.16; Jour. Soc. 
Chem. Ind., 1901, p. 564; 1902, p. 1077. 



SPECIAL CHEMICAL AXD PHYSICAL METHODS. 203 

washed into a Becker glass with 500 c. c. of hot water, cooled, 
and filtered through a damp filter. The Becker glass and 
filter are washed with cold water until barium chloride indi- 
cates no cloudiness. 

The filter is allowed to drain well, is thoroughly wetted 
with absolute alcohol, and the paraffine washed out by pour- 
ing ether through the filter into a tared dish until a drop of 
the escaping ether when evaporated leaves no residue. Also 
the last particle of paraffine is removed from the Becker glass 
by means of ether. 

The ethereal solution will soon evaporate in a warm 
place, the residue dried therein for a half hour and the paraf- 
fine weighed. * 

Richardson and Holde. 

Clifford Richardson has applied the method proposed by 
Holde for the determination of paraffine in oils, to a research 
upon "The Determination of Paraffine in Petroleum Residues, 
and Asphaltic Oils and Asphalts Fluxed with Paraffine Oils." 
For this purpose I, 2 or more gms. of the substance to be 
examined -are taken and treated in an Erlenmeyer flask with 
100 c. c. of 88 petroleum naphtha. The naphtha is allowed 
to act on the substance over night and the next morning the 
solution is decanted through a Gooch crucible, the residue 
washed with naphtha and the solution and washings united, 
and shaken in a capacious separatory funnel with sulphuric 
acid of sp. gr. 1.84 until a new portion of the acid is no longer 
colored. As a rule two washings are sufficient. The paraffine 
solution is washed with water, then with a weak solution of 
sodium carbonate and again with water; in this manner the 
mixture of paraffine and asphalt hydrocarbons, freed of all 
unsaturated hydrocarbons, is isolated by evaporation of the 
solvent. 

According to the method of Holde, the residue is taken 
up with ether and the asphalt hydrocarbons are precipi- 
tated therefrom by addition of alcohol. The paraffine is ob- 
tained in a pure state by evaporation of the filtrate. 

Determinations by this method gave the following re- 
sults : 



"Muspratt Chemie, 4 orl., vol. 8, p. 70. 



204 SOLID BITUMENS. 

PETROLEUM RESIDUUM FROM PIPE LINE OIL. 

Sp. Gr. 0.93. 








Per cent of 


Per cent 




Weight 


Soluble in 


Not Acted on Per cent of 




G. 


Naphtha. 


by HUSO*. Paraffine. 


No 1 


11 


96 


No treatment 7.95 


No. 2 


11 


96 


89.5 5.55 


No. 2 


11 


Distilled in vacuo 


No treatment 5.95 



TRINIDAD ASPHALT CEMENT. 

Per cent of Per cent 

Weight Soluble in Not Acted on Per cent of 

G. Naphtha. by HUSO*. Paraffine. 

No. 1 ......... 10.0 ........ Not washed 2.95 

No. 2 ......... 10.0 ........ Not washed 0.95 

In every case the recovered paraffine, after treatment with 
acid, was white, and pure, whilst by means of vacuum distil- 
lation it muld only be obtained colored. The results were 
something lower, but more correct than those obtained by 
vacuum distillation. 

The Trinidad asphaltic cement was made from 100 parts 
Trinidad* asphalt and 20 parts petroleum residuum contain- 
ing 5-55 P er cent f paraffine. The Trinidad asphalt was 
paraffine free, the calculated amount in the cement was 0.925 
per cent whilst 0.95 per cent was found.* 

ARTIFICIAL ASPHALTS. 

The artificial asphalts, as a rule, contain free carbon, in 
an amorphous condition as an insoluble constituent; proceed- 
ing from decomposition incident to the destructive distillation 
of organic substances, with which a greater or less quantity 
of ash constituents are rarely associated. 

The determination of the soluble bitumens of artificial 
asphalts can be made in a similar manner as with the nat- 
ural asphalts, with this difference, that, as a rule, the con- 
tent of free carbon is ascertained and the quantity of bitu- 
men calculated out of the difference. With the artificial as- 
phalts which have been obtained through distillation of 
mineral coal from common coal-tar through all stages to coal- 
tar pitch, the ascertaining of the proportion of soluble bitu- 
men is generally practicable" only by a calculation of differ- 

*Journal Soc. Chem. Ind., 1897, p. 16; 1902, p. 690. Mitteil aus der KSnigl. 
Versuchsanstalt zu Berlin, 1896, p. 211. 



SPECIAL CHEMICAL AND PHYSICAL METHODS. 205 

ence, because by the evaporation of extracts, and particularly 
by drying the residues from the distillation, such volatile sub- 
stances as the low boiling hydrocarbons, and also those with 
high boiling points like naphthalene are lost. 

As a rule the object is obtained when the product is 
boiled out with twenty times the quantity of benzole hydro- 
carbon (xylol) and brought upon a filter with water white 
hot hydrocarbon and washed out until the filtrate flows un- 
colored. 

Kohler (Ding. Poly. Journal 270, p. 233) has found a 
mixture of equal parts of Toluole and glacial acetic acid to 
answer the purpose. Kraemer and Spilker (Muspratt Chemie 
4 Edition, Vol. 8, p. 3) as a most convenient practical method 
offer the following: 

Warm one part of tar or of the pulverized artificial as- 
phalt with 3 parts anilin and pour the semi-fluid mass upon 
a small plate of burned unglazed porcelain. The solvent to- 
gether with the soluble constituents of the tar or pitch will 
be absorbed by the porous mass, while the insoluble carbon 
remains behind as a laminated mass, that, with a small 
wooden spatula can be brought without loss upon a tared 
watch glass, that after more than an hour in the water bath 
will be brought to weight. According to the above named 
authors, the extraction of bitumen by means of anilin is more 
complete than by means of the previously mentioned hydro- 
carbons. 

DISTINGUISHING BETWEEN ARTIFICIAL 
ASPHALTS. 

Davies. 

The difference between the artificial asphalts out of coal- 
tar pitch, brown-coal-tar pitch, wood-tar pitch and candle-tar 
pitch, is determined by slightly heating the bitumen over an 
open flame. The escaping odor is characteristic of each pitch 
and quickly reminds one in the tar pitches of the specific 
smoke of the respective tar, and for candle-tar pitch, of 
burning fat. Their behavior with petroleum benzine is also 
useful, in which coal-tar pitch is the most difficultly soluble 
and in the smallest quantity, whilst brown-coal-tar pitch is 





Soluble. 


Insoluble. 


Ash. 


Sulphur. 




Per cent. 


Per cent. 


Per cent. 


Per cent. 


1 


2444 


75.56 


0.20 


0.69 


9 


1870 


81.80 


1.06 


0.41 


3 


16.86 


84.14 


0.48 


0.59 




71.05 


28.95 


5.50 


0.04 



2o6 

nearly wholly soluble therein. The behavior of the wood-tar 
and candle-tar pitches, in these solvents is, according to 
Davies, as shown in table :* 

In Petroleum Benzine. 



Wood-tar Pitch, 1 
Wood-tar Pitch, 2 
Wood-tar Pitch, 3 
Candle-tar Pitch 

According to Buchanan even the origin of the different 
kinds of coal-tar pitch (coke-oven or gas or blast furnace tar), 
can be determined with certainty through the percentage of 
ashes. Tar pitch never contains more than o.i per cent, the 
latter 6.8 per cent to n.i per cent of ash; if then, a coal-tar 
pitch contains less than I per cent of ash, it is certainly no 
coke-oven pitch. As the asphalt industry involves the co- 
hesive strength and elasticity of all these kinds of pitch this 
remark is not without interest. y 

Separation of the natural and artificial asphalts and proof 
of the latter in mixture with the former. 

In order to ascertain the difference between coal-tar pitch 
and natural asphalt (the mixture seldom contains brown-coal- 
tar or wood-tar pitch), in most cases it is sufficient to heat 
the sample in a crucible, at the same time distinguishing the 
heavy stinging odor of the coal-tar pitch from the bituminous 
odor of the natural asphalt. Very characteristic also is the 
conspicuous green-blue fluorescence which appears in a weak 
solution of the tar-pitches in benzol, carbon bisulphide, 
chloroform, benzine, and especially acetone. J 

MICROSCOPE. 

Meinecke. 

As E. Meinecke has shown, the microscope also reveals 
the nature of the molecular condition of the asphalt. He 
spreads the microscopic preparation upon a heated slide. 
Syrian asphalt exhibits when viewed under the microscope, 

*Chemist and Druggist, xxv, p. 504. Scheithauer, Muspratt's Chemle, 4 
eel., vol. 6, p. 1982. 

tJour. Soc. Chem. Ind., 1894, p. 1098. 

iLunge-Kohler, Ind. des Stein Kohlen Teers u. Ammoniaks, 4 ed. 1, p. 436. 



SPECIAL CHEMICAL AXD PHYSICAL METHODS. 207 

a yellow-brown, transparent, homogeneous mass. Quite sim- 
ilar, yet not so intensely colored, appears the brown-coal-tar 
pitch under the microscope, while coal-tar pitch contains in- 
numerable particles of carbon, that stand out against the 
golden yellow ground. In Trinidad asphalt is found a yellow- 
brown ground with larger and smaller little kernels of min- 
eral matter, between which are small particles of -an unknown 
nature (coal?). Viewed through crossed NicoFs prisms, the 
prepared slide gives nothing of striking value.* 

SPECTROSCOPE. 

Kayser. 

According to R. Kayser the spectroscopic deportment of 
the different asphalts is a satisfactory means by which to 
distinguish the natural from the artificial products. Con- 
cerning the nature of this research, he refers to H. W. Vogel's 
"Praktische Spektral-analyse irdischer Stoffe.'' For research 
upon the absorption spectra, Kayser recommends a solution 
of the asphalt in chloroform of a slight intensity of color. 
Figs. 3 to 14 exhibit a graphic representation of the results 
obtained by those experiments. Especially characteristic of 
Syrian and Trinidad asphalts are the lines between D and 
E, with a, /3 and y, indicating absorption bands, by which 
upon thin solution in spirits of wine and ether these constitu- 
ents are separated as the same bands are not shown in the 
insoluble portion. The portion soluble in alcohol is differ- 
entiated from that soluble in ether by the strong absorption 
band y, which does not appear in the ether solution, al- 
though the latter exhibits the ft band much stronger. 

The absorption spectra of the asphalt of Pechelbronn 
'and its constituents, as well as the asphalts out of coal-tar do 
not. show this band.f 

The preceding pages (196 to 207) present a series of em- 
pirical tests that taken separately are of little value, but when 
used successively in a series, and especially when undertaken 
by an experienced manipulator, furnish conclusive evidence as 
to the kind of pure or mixed bitumen under examination. 

*Chem.-techn. Untcrs. liber Triniclacl-goudron, Biebrich, Verlag von Mattar 
u. Gaszmus. 

tlOc cit. p. 29; D. H. Kohler Chem. u. Tech. der natiirlichen u. KUnstllchen 
Asphalte, Brannschweig, 1904, p. 346. 



208 



SOLID BITUMENS. 



Quantitative results are only approximately satisfactory, yet 
they are not without value. 

I make the following comments on the different tests 
mentioned. 

In general it may be stated that brown-coal-tar pitches 
are almost unknown in the markets of the United States. 
Straight coal-tar pitches are less rarely used than those pro- 



E y 3 a D C B 







"-vj 


s, 






















N 






















\ 


X 









Fig. 3. Asphalt of Bech- 
elbronn. 



Fig. 4. Petrolene from 3. 



Fig. 5. Asphaltene 
from 3. 




Fig. 6. Coal Tar Asphalt. 



ceeding from a modified process for producing gas in which 
the distillation of coal is supplemented in various ways. 
To these are added coke-oven-tar pitches and blast-furnace- 
tar pitches, thus furnishing a variety of pitches that give 
modified and slightly varying results that have a general 
likeness to each other and difference from true asphalts and 
petroleum pitches. 



SPECIAL CHEMICAL AND PHYSICAL METHODS. 209 

While specimens of factice, whether from coal-tar or 
petroleum are likely to contain particles of fixed carbon or 
soot, their absence, proved by solution and filtration, is by no 
means proof that the bitumen is a true natural asphaltum. 

Factice of a very excellent quality, that is stable, tena- 
cious, elastic at two temperatures, and that melts at compara- 
tively high temperatures, that does not contain a trace of coke 
or soot, is sometimes met with. 



a D C B 



Fig. 7. Trinidad Asphalt. 




Fig. 8. Alcoholic Solu- 
tion of 7. 







\ 




/ 


\j 


1 









. 9. Ether Solution 
of 7. 



10. Insoluble Resi- 
due from 7. 



The suphuric-acid test of Durand-Claye is very valuable. 
I use 25-c.c. graduated and stoppered jars in which to secure 
action for 24 hours on o.i gm. of the bitumen, by 5 c. c. of 
fuming sulphuric acid. After standing 24 hours the acid solu- 
tion is diluted and carefully filtered through a wet filter, into a 
graduated cylinder and the solution made up with water to 15 
c.c. In order to determine the value of the color imparted to the 



2IO 



SOLID 1UTUMEXS. 



solution great care should be taken that the different steps in 
the process shall be as nearly identical as possible. The best 
means of concentrating the bitumen is by means of an elec- 
trical stove set to be heated by the same current. The evap- 
oration should be conducted throughout under as nearly the 
same conditions as possible. Each of the different steps in 
the entire process should be duplicated as nearly as possible. 
Dilution of the solution to 100 c.c. is not necessary, and it 

G F Ev/SaDCB 



Fig. 11. Syrian Asphalt. 







\ 


/ 


\J 


\J 


\ 













\ 


1 


\! 


J\ 









Fig. 



12. Alcoholic Solu 
tion of 11. 




Fig. 



13. Ether Solution 
of 11. 



Fig. 



14. Insoluble Resi- 
d*e from 11. 



destroys the characteristic shades of color that distinguish 
the natural asphalts from each other and leaves only the dis- 
tinction of the highly colored tar-pitches from the light col- 
ored natural bitumens. Every one who uses this test should 
carefully prepare a series of test solutions which should be 
put in receptacles of colorless glass of uniform diameter. 
These should be kept in a convenient place for reference and 
ranged with labels from the darkest to the lightest. 



SPECIAL CHEMICAL AND PHYSICAL METHODS. 211 

Results obtained by the benzine-alcohol method are good 
for comparison. 

So also is the precipitation method of Kovacs and Sotet. 
Both methods require experience and close observation of 
minute differences, which with other tests furnish cumulative 
evidence. 

A microscope of low power also furnishes results that are 
valuable adjuncts to chemical tests. I have found that small 
fragments of all varieties of bitumen placed on a slide and 
moistened with a few drops of chloroform furnish characteris- 
tic reactions while undergoing solution. The undissolved por- 
tions are very peculiar to each species and help, with the other 
characteristics that must be observed to be recognized, in the 
determination of any given specimen. 

The spectroscope has not yet been found especially valu- 
able, but it has not yet been sufficiently tested to submit to final 
judgment. 



CHAPTER XIV. 

MISCELLANEOUS METHODS APPLIED TO STREET 
MIXTURES AND SURFACES, BITUMINOUS PAV- 
ING BLOCKS, BITUMINOUS CONCRETE, WOOD 
PAVING BLOCKS, CEMENTS, CEMENT MOR- 
TARS AND CONCRETES, ETC. 

Street mixtures and surfaces, bituminous blocks and con- 
cretes are mixtures of a mineral aggregate, pulverized rock or 
its equivalent, and bituminous mixture of some sort. 

The analysis is technical and proximate. It may be par- 
tial or complete. 

The sample should never be pulverized. Under all con- 
ditions and for all purposes, the physical condition of the sam- 
ple should be changed as little as possible. If the only ques- 
tion to be answered is, simply, what is the percentage by 
weight that is soluble in carbon bisulphide, nothing is gained 
by destroying the identity of the mineral residue through pul- 
verizing the sample. When it is desired to learn all that can 
be learned about a sample, the sample should be broken only 
sufficiently to secure an average or to put the sample into a 
wide mouthed flask. 

When the sample is a street surface, about 100 gms. 
should be broken from different parts of the mass, taking care 
to exclude any binder or fragments of gravel that may have 
become embedded in the mass. Care should also be taken to 
secure an average of the mass from top to bottom, as no sur- 
face that has been laid longer than a few months is of uniform 
composition. These fragments should then be rubbed on a 
flat-bottomed iron motar. It should not be pounded or rubbed 
more than is necessary to bring the sample to a uniform 
coarse powder in which the grains of sand are unbroken. Ex- 
perience will teach the operator that much may be learned, as 
to the quality of a surface from its action under the pestle of 
an iron mortar. Surfaces and mixtures of good quality are 
never easily broken ; they are n'ot only tenacious, but after 

212 



MISCELLANEOUS METHODS. 



213 



being broken, the fragments, whether large or small, readily 
cohere and again become a solid mass. Poor and dry surfaces 
and mixtures on the contrary are readily broken and will co- 
here only slightly if at all. Good surfaces or mixtures do not 
easily soil the fingers at ordinary room temperatures, while 
surfaces containing an excess of flux, and those that are too 
soft are sticky and stain the ringers. These dry surfaces and 
mixtures rub in the mortar like sugar ; while the sticky ones 
roll into balls and are sometimes greasy, and while not easily 
reduced to small particles are not strong and tenacious. 

Portions of 5 gms. each, are weighed in duplicate into bal- 
anced filters, and placed in stoppered funnels. They are then 
treated precisely as described on page 154 for crude asphalts 
either with one solvent or more, as is desired. 

For ordinary purposes, 100 gms. is a sufficient quantity 
of the material of an asphalt paving block to use for an an- 
alysis. If, however, an examination is to be made of the min- 
eral aggregate, 500 gms., or even 1,000 gms., may be taken for 
that purpose. The most satisfactory procedure, is to put the 
material into an Erlenmeyer flask of suitable size, broken as 
little as is possible. Bisulphide of carbon is filled into the 
flask with vigorous shaking, after which the solution is al- 
lowed to stand several hours or over night. When settled the 
supernatant liquid is poured off into a second flask, and more 
CS 2 added to the first flask with agitation. After standing, 
the solution is again decanted and a third portion of the sol- 
vent is poured upon the residue. This third portion is gen- 
erally found to be sufficient. The residue is dried. The mixed 
solutions are allowed to stand until subsidence is complete ; 
the liquid decanted ; the fine residue rinsed upon a filter and 
washed with a last portion of CS 2 . The filter is dried, un- 
folded on to a balance pan, the dried residue swept on to it 
from the flask, and weighed, with the filter balanced by a 
second paper in the pan that receives the weights. A good 
balance, that is sensitive to a tenth of a gram, gives sufficiently 
accurate results. 

The clean and dry mineral aggregate is in excellent con- 
dition for examination by sieves or under the microscope. 

The solution may be evaporated and the bitumen may be 
further examined as ma v be desired. 



214 SOLID BITUMENS. 

Bituminous concretes may be treated in the same manner 
as asphalt paving blocks. 

Both asphalt paving blocks and concretes may be treated 
in large separatory funnels. The solution is tedious as some 
of the bituminous mixtures filter slowly. The fine mineral ag- 
gregate that passes the filter must always be recovered by de- 
cantation. The only recommendation for this method is the 
large size, and consequent unbroken mineral aggregate, that 
may be received into the open funnels. 

The analysis of wood paving blocks is a special problem 
that has received careful study in the Laboratory of the Com- 
missioners of Accounts of the city of New York. As in other 
cases the selection and preparation of a sample was found to 
be of the greatest importance. In all commercial lots of 
treated wood blocks that we have seen there were a few, to 
many that were not "thoroughly treated." The external ap- 
pearance of these blocks was no indication of their interior con- 
dition as in all cases the outside was covered with the fluid 
used for treatment. All of the solvents used to extract this 
fluid dissolved an appreciable amount of resin and other ex- 
tractive matters, including water from untreated blocks of 
yellow pine, and an attempt was made to determine an average 
amount of this extract. The amount was found to vary to 
such an extent as to present very wide extremes in any half- 
dozen blocks taken at random. 

While this investigation was in progress a great variety 
of solvents were used in extracting both the treated and un- 
treated blocks, including petroleum ether, benzole and its 
homologes, alcohols, bisulphide of carbon, etc. They were all 
discarded for various reasons and pure acetone was used in 
their place. This liquid is easily procured, is cheap and is so 
volatile as to be easily and completely removed from the ex- 
hausted residues. The apparatus used consists of the revolv- 
ing support and separatory funnels described on page 186. 

The only way in which samples could be prepared from 
which duplicate results could be obtained on analysis, was 
found to be by sawing through the block across the grain of 
the wood and thoroughly mixing the sawdust. In general, 
three such cuts through a block gives a fair average of the 
treatment of the block; but, it is frequently found that, from 



MISCELLANEOUS METHODS. 



215 



blocks that are well treated the sawdust from the three cuts 
is unlike, while blocks that are indifferently treated furnish 
very different results from the three cuts. 

These remarks apply only to blocks.treated with a mixture 
of rosin and dead oil ; from straight coal-tar. Acetone will not 
dissolve water-gas-tar, and other tars and residual pitches that 
are often used to saturate wood blocks. 

Blocks that are treated with the dense residuum oil, from 
the distillation of creosote oil, cannot be completely extracted 
with acetone. Chloroform is the proper solvent for these 
blocks. 

It has been sometimes found necessary to examine the 
creosote oil used for impregnating wood blocks, and other oils 
and tars of high boiling points, as well as malthas that are 
very dense and also of high boiling points, in such a manner as 
to separate their proximate principles and thus furnish some 
information respecting their fitness or unfitness for use in im- 
pregnating compounds. 

The apparatus that experience has shown to be most suit- 
able for this purpose is very simple, and at the same time, must 
fulfill certain conditions that cannot be overlooked. An 8- 
ounce (250 c. c.) retort should be selected, of Jena glass, with 
a bulb as nearly spherical as possible, with a tubular that has 
no stopper. Into the tubular should be fitted^ a soft cork. A 
tightly fitting thermometer stem should pass through the cork, 
the bulb of which should reach within half an inch of the sur- 
face of the liquid that is to be distilled. A cylinder should 
next be provided of any non-conducting material of about 4-in. 
internal diameter and 5-in. high. I use a graphite cylinder, but 
one made of sheet iron and lined with four or five thicknesses 
of heavy asbestos paper, that can be coiled compactly into a 
circular lining is just as good. A slot is cut clown about 2y 2 
inches deep on one side to receive the neck of the retort. A re- 
tort stand is provided with a ring of about the same diameter 
as the cylinder, over which is spread a piece of coarse wire 
gauze. Upon this gauze is spread a thin cushion of asbestos 
fiber, upon which the retort is placed. The charge of about 100 
grams is either weighed or measured into the retort, the retort 
placed in the cylinder, the thermometer stem adjusted, and the 



2l6 



SOLID BITUMENS. 



top of the retort lightly covered with asbestos fiber. The 
thermometer should register above six hundred degrees. 

The condenser should be a tube about one centimeter in 
diameter and about thirty inches long, swelled at one end to re- 
ceive the neck of the retort. For the purpose for which this 
apparatus is used it is not necessary to use water as a con- 
denser. The air at the temperature of the room is sufficient. 
Many of the substances condensed are solid at ordinary tem- 
peratures and would plug the tube of an ordinary Liebig's con- 
denser, if completely cooled. 

The distillate should be received into small, graduated 
cylinders, which admit of dividing it into small fractions. 




Fig. 15. Retort and Graphite Hood. 

Either a one, three, or six tube Bunsen's burner may be 
used for heating the charge ; ordinary care being exercised lo 
regulate the heat in proportion to the rapidity of the flow. 

If it is desired to estimate the distillate in fractions by 
weight, the fractions may be received into small crystallizing 
basins that have been tared, and then weighed. 

This apparatus will be found very useful in the examina- 
tion of all bitumens that yield distillates that condense at the 
temperature of boiling water or above it. 

Fig. 15 shows the apparatus in section. 

The following is a description of the manner of using the 
apparatus represented in Fig. 15. One hundred grams 
are placed in the retort, (either by weight or measure) and are 
warmed cautiously until the water is expelled, and then heated 



MISCELLANEOUS METHODS. 217 

until the rate of distillation is about two drops per second. 
The distillate is collected in tared glass dishes that may be 
either graduated cylinders or crystallizing basins. Notes are 
taken of the amount of distillate between 
o and 315 Centigrade. 
Above 315 Centigrade. 

As the distillation proceeds, after the water has been re- 
moved, the phenols come over a little above the boiling point 
of water; then naphthalene appears as a yellow crystalline 
solid, that is followed by a greenish yellow solid containing an- 
thracene. The last portion of the distillate is a dark brown 
oil. 

The genuine creosote oil is readily distinguished from the 
water-gas-tar and other similar residuums that have lately 
been substituted for it, in the treatment of wood blocks. While 
the distillate from creosote, or dead oil, is always as above de- 
scribed, the distillates from the tars and residuums contain lit- 
tle or no phenols, naphthalene or anthracene. They consist of 
a much smaller total percentage of dark brown oils, free or 
nearly free from solid matter. 

The value of these tars and residuums that are practically 
free from phenols, anthracene and naphthalene has yet to be 
determined. 

Much remains to be learned concerning this subject. 

The mineral aggregates are separated by sifting. They 
may be determined by weight in percentage proportions from 
the residues on the different sieves. A low power microscope 
frequently furnishes valuable information and more rarely, a 
chemical analysis is desirable. 

A METHOD FOR A CORRELATION OF THE PHYS- 
ICAL AND CHEMICAL EXAMINATION OF 
CEMENTS, CEMENT MORTARS AND 
CONCRETES. 

Before proceeding to a dicussion of the subjects embraced 
under this title, I would designate several topics that I wish to 
bring clearly before the reader as neither directly nor indi- 
rectly involved in such discussion. It is my intention to dis- 
cuss a series of technical problems from a purely technical 
standpoint. These problems relate solely to the use of cements 



218 SOLID JIITL'MEXS. 

in mortars and concretes. In the operations or results attend- 
ing the use of cements it is of no importance whether the lime, 
silica, alumina and iron are in one manner of combination or 
another, whether they are in intimate mechanical admixture or 
"solid solution," no matter how important or interesting these 
problems may be to the theoretical chemist or to the manu- 
facturer of cement who makes his mixtures to conform to one 
formula or another. The one who uses cement applies it to 
certain uses and determines its fitness for such uses by means 
of certain tests that give him valuable data without any in- 
quiry concerning theoretical problems. 

I propose to discuss the determination of a method for a 
comparative analytical examination of cements, cement mor- 
tars and concretes correlative with their properties as revealed 
by physical tests. A brief review of the most important re- 
searches prosecuted in recent years will not only show the 
lack of any correlation between the chemical and physical ex- 
amination of cements, but will further show, that no attempt 
has been made to bring an examination of mortars and con- 
cretes into correlation with either the chemical or physical 
examination of the cements from which they are made. 

It is impossible to enumerate here all of the attempts and 
the results of the attempts, made in the United States and 
Europe in recent years, to formulate a method of analysis that 
shall fully satisfy all the parties interested in the analysis of 
cements. It is only necessary to consult the literature of the 
subject to discover that such attempts have not been satis- 
factory. In many instances the want of correlation between 
the chemical and physical tests are either frankly confessed or 
are not mentioned. From this multitude of varying proposi- 
tions, in which, often, the points of difference are more notice- 
able than those of agreement, I select as most important the 
reports to the New York section of the Society for Chemical 
Industry by their sub-Committee on Uniformity of Analysis 
of Materials for the Portland Cement Industry, and the reports 
of the special committee on the proper manipulation of tests 
of cement made to the American Society of Civil Engineers. 
To properly show the relation of these reports requires a few 
words of explanation. At a date prior to April, 1900, the 
American Society of Civil Engineers appointed a special com- 



MISCELLANEOUS METHODS. 219 

mittee of which Prof. George F. Swain, Prof, of Civil Engi- 
neering in the Massachusetts Institute of Technology, was 
chairman. This committee made a progress report which was 
published in the Proceedings of the Society, Vol. XXVI, No. 
4, April, 1900. 

This report consists of the various replies to a long list 
of questions offered by many persons, and submitted by the 
chairman of the committee, Prof. G. F. Swain, without com- 
ment. From this report is quoted the 

Scheme of Prof. Henry Carmichael. In reply to Question 
5 (one of the above-named questions), 

What elements ! of compounds should be determined? 

Professor Henry Carmichael of Boston, Mass, (who is an 
acknowledged authority as a cement expert), says: 

"Hydraulic cement consists of a double silicate of lime 
and alumina (including iron oxide), which is readily soluble 
in dilute hydrochloric acid, leaving little or no insoluble resi- 
due. In addition to the soluble silica and the oxide of calcium, 
aluminum and iron, good cement contains traces of the ox- 
ides of magnesium, sodium and potassium, together with 
traces 'of carbonates, sulphates, chlorides and combined water, 
and finally minute amounts of insoluble sand or cinder." 

In reply to Question 6, 

"What do you consider the best methods of determining 
these compounds with sufficient accuracy?" 

Prof. Carmichael continues: 

"The sample is ground fine in an agate mortar. One 
gram is carefully weighed out in a shallow porcelain dish and 
well covered with a 3 per cent solution of hydrochloric acid. 
After several hours the cement should completely dissolve in 
this acid with the exception of a small amount of sand, mostly 
black cinder, from the fuel employed in making the cement. 
The residue, if any, is filtered off and determined. The clear 
solution is evaporated to dryness on a water bath in a flat 
dish. Hydrochloric acid is poured over the dry residue, and 
the acid is then evaporated. Add a few drops of same acid, 
again drive off acid. Moisten residue again with same acid 
and boil up with pure water. The silica is rendered insoluble 
by the above operation and can be filtered off and weighed. 
The silica which thus dissolves in the dilute acid, ami is in 



220 SOLID 1UTCMLLXS. 

turn rendered insoluble, is the silica which is available in the 
setting of the cement. The filtrate from silica is boiled with 
a few drops of nitric acid, and pure ammonia is then added, 
which precipitates the oxides of iron and aluminum. With the 
ammonia is added also ammonium chloride in sufficient quan- 
tity to retain the lime in solution. After boiling- for some time, 
the oxides of iron and aluminum are filtered off, and after dry- 
ing are ignited and weighed." 

Here follow directions for separating the iron and alum- 
inum: 

"To the filtrate from iron and aluminum oxides is added a 
slight excess of ammonium oxalate, whereby the lime is pre- 
cipitated as oxalate which is filtered off, ignited at a dull red 
heat in a platinum crucible and weighed as carbonate." 

His scheme offers further details for the determination of 
the ingredients that he says are found in good cements in 
traces; for the determination of water and carbonic acid by 
ignition ; and for the determination of free lime by titration. 

I quote further the 

Scheme of R. L. Humphrey. "One-half gram of the finely 
pulverized sample dried at 100 C, is thoroughly mixed with 
four or five times its weight of sodium carbonate, and fused in 
a platinum crucible until CO 2 no longer escapes ; the crucible 
and its contents is placed in a beaker, and twenty or thirty 
times its quantity of water, and about TO c. c. of dilute HC1 
is added; when complete solution is effected, it is transferred 
to a casserole and placed on a water-bath, and evaporated to 
dryness several times. The mass is taken up with dilute HC1 
and water, heated for a short time and filtered thoroughly, 
washing the residue on the filter with hot water. The filter is 
dried, ignited and weighed. This weight (less ash) gives the 
amount of SiO 2 ." 

"The filtrate is brought to boiling and ammonium hy- 
drate added in slight excess, the boiling is continued until the 
odor of ammonia is no longer perceptible. Filter and wash. 
Redissolve in hot dilute HC1, again precipitate with ammonia 
and filter through the previous filter and wash with boiling 
water. The precipitate dried, ignited and weighed, less ash, 
gives the amount of A1 2 O 3 and Fe 2 O :{ " 

Then follows a method of separating iron from alumina : 



MISCELLANEOUS METHODS. 221 

"The nitrate from the iron and alumina is heated to boil- 
ing, and boiling ammonium oxalate is added until a precipitate 
is no longer formed. After boiling for a few minutes, it is set 
aside for a short time ; when the precipitate has settled per- 
fectly, decant the clear liquid through a filter, wash by decan- 
tation, dissolve the precipitate in hot dilute HC1, using as 
small a quantity as possible to effect a complete solution; heat 
to boiling and add ammonia ; heat on a water-bath for a few 
minutes; when the solution* clears, filter through the previous 
filter, wash thoroughly with hot. water. Dry the precipitate, 
ignite to constant weight, and weigh as CaO, or determine the 
lime volumetrically by titration with potassium perman- 
ganate." 

He then determines the ingredients occurring in small pro- 
portion. He determines SO 3 in a separate portion after re- 
moving the silica. 

In the Journal of the Society of Chemical Industry for 
January 15, 1902, page 12. will be found the report of the sub- 
Committee on Uniformity in Analysis of materials for the 
Portland Cement Industry. This committee consisted of Clif- 
ford Richardson, S. B. Newberry and H. A. Shaffer. They 
sent out a circular asking the chemists addressed to join them 
in analyzing samples of raw cement mixture and finished Port- 
land cement, "sending your results and a description in detail 
of your methods of analysis * * *. From comparison of 
the results and methods which are recorded it is hoped that 
some uniform method can be arranged which can be relied 
on for general use so that such discordant results as have been 
obtained at times in the past may be avoided." To this cir- 
cular eighteen chemists responded of whom thirteen were 
chemists to manufacturers of Portland cement, one was one 
of the chemists to the Geological Survey at Washington, Dr. 
Hillebrand, and the other four sustained relations to the sub- 
ject unknown to us. 

The results obtained by these gentlemen were very vari- 
ous and their methods were equally so. One used a general 
method for rock analysis, which was of course ultimate. Seven 
fused the assay; four powdered it; two dried it; three dis- 
solved it in dilute acid ; six dissolved it in strong acid, while 



222 SOLID lUTL'MEXS. 

only two specifically stated that they treated the sample of 
cement as it was received. 

After reviewing these various methods and results Dr. 
Hillebrand reaches the following conclusions : 

Dr. Hillebrand's Conclusions. "The chief conclusions de- 
rived from a critical examination of all the data reported are 
embodied in the following summary of rules, and they bear 
out fully the views long since formed and frequently pub- 
lished by myself. 

"To the non-observance of these rules, coupled with in- 
complete washing, of precipitation, and perhaps in some cases 
the employment of impure reagents are to be attributed nearly 
every one of the more or less marked variations in the tabu- 
lated analyses. 

"(i) Cement samples whose composition is to be con- 
trolled by different chemists should be sealed air-tight and not 
opened until the analysis is about to be made. 

"(2) Mode of Attack. Limestone and raw cement mix- 
tures should be heated over the blast in order to render them 
wholly soluble and to oxidize sulphides and organic matter. 
If any residue should remain on treatment with hydrochloric 
acid (with finished cements as well) this should be collected 
without evaporation and fused with a minimum of sodium 
carbonate, its hydrochloric solution being added to the former. 

"For sulphur an oxidizing attack, either in the wet or dry 
way, must be used with both limestone and cement in order 
to obtain all the sulphur. 

"(3) Separations. (a) Without two alternating evapo- 
rations and filtrations it is impossible to obtain a correct re- 
sult for silica, no matter how or at what temperature dehydra- 
tion has been conducted. The blast should always be applied 
for at least ten minutes, and in careful work correction by 
hydrofluoric and sulphuric acids should not be neglected. 

"(b) Iron and aluminum, with any titanium and phos- 
phorus present, should be twice precipitated by ammonia in 
presence of sufficient ammonium chloride to retain magnesium 
in solution. Without this double treatment very appreciable 
amounts of lime will contaminate the alumina. If manganese 
is present in more than traces it is advisable to add bromine 
before the ammonia, so as to weigh most of the manganese 



MISCELLANEOUS METHODS. 



223 



with the alumina rather than with the lime and magnesia. Ap- 
plication of the blast is advisable. 

"(c) Iron cannot be accurately determined volumetrically 
or by weight, in presence of titanium if zinc is employed for 
its reduction. Hydrogen sulphide should be used and all ex- 
cess boiled out in a current of carbon dioxide. 

"(d) In accurate work lime should be twice precipitated, 
whether it is to be determined volumetrically or by weight, 
and at least one hour should intervene between precipitation 
and filtration. Compensation of errors affords satisfactory 
results in the hands of few operators with but a single separa- 
tion from magnesium. 

"(e) Magnesium pyrophosphate is only to be obtained 
of normal composition after long blasting (Neubauer), when 
precipitated under the conditions prevailing in technical an- 
alysis, that is, in presence of much ammonia and ammoniacal 
salts, especially the oxalate. 

"Strict observance of all the above rules is doubtless often 
impossible in the hurried routine of a technical laboratory, but 
the inevitable penalty of material deviation from them is a 
decrease in the accuracy of the results." 

Dr. Hillebrand then offered some "Suggestions regarding 
Scheme of Analysis submitted by Mr. Clifford Richardson," 
as follows: 

Dr. Hillebrand's Suggestions. "The title should cover 
analysis of limestones and limestone mixtures as well as fin- 
ished cements. 

"Paragraph I should prescribe the ignition of limestone 
and raw mixtures and the fusion of any residue (from cements 
also) that may be insoluble in hydrochloric acid with a small 
amount of sodium carbonate, and the addition of the hydro- 
chloric acid solution of this fusion to the former. From this 
point the procedure should be identical in both cases. 

"SiO 2 . The time of blasting silica can be very well short- 
ened to a maximum of 10 minutes, without further check, when 
but Y-2. gm. of sample is operated on. The weight of silica will 
rarely exceed i decigram and 10 minutes should suffice for its 
complete dehydration over a good blast. 

"The strength of HC1 solution used in the silica evapora- 
tion should be stated approximately. I should call 5 c. c. of 



224 SOLID BITUMENS. 

acid of 1.12 sp. gr. much too little to use, for it would only 
contain about i gm. of HC1. It should be made clear that the 
evaporated residue is to be digested with the acid a little while 
before further diluting. 

"ALOjj, etc. It is perhaps hardly necessary for a technical 
analysis to prescribe that the precipitate shall be dried and 
removed from the filter, though this might be recommended 
for the best work. 

"Fe 2 O 3 . The H 2 S method of reduction should be pre- 
scribed for the best work. 

"FeO. For technical work it does not seem necessary to 
prescribe any rule for FeO. 

"CaO. The time allowed for settling the first CaCO 4 
precipitate (2 hours) is quite too much if a second precipita- 
tion and filtration are to be made the same afternoon. The 
time schedule is in error on this point. The "outline" makes 
it appear that the full flame is applied at once to the moist 
CaC 2 O 4 precipitate wrapped in its paper. I know that this 
is done by some European chemists with ammonium mag- 
nesium phosphate, but I should question its advisability here. 

"Blasting for 10 to 15 minutes without any further check 
ought to be sufficient to reduce the CaO. Personally I never 
find more than 5 to 10 minutes' blasting necessary. I do not 
insist on this point, but offer it in interest of time saving. 

"MgO. After the precipitate has formed I should add 
more than three or four drops of ammonia to hasten complete 
precipitation. With all the ammonium salts present I regard 
it as useless to follow strictly the directions of Gibbs, Gooch 
and Austen, for precipitating Mg, and would rely on long 
blasting to secure normal Mg 2 P 2 O 7 . It should be stated that 
dilute ammonia water is used for washing. 

"When a Gooch crucible is used I should hesitate to rec- 
ommend the blast, at least unless it is well known that the as- 
bestos undergoes no change at this high temperature. Some 
asbestos which stands the Bunsen flame will not endure that 
of the blast. 

"SO 3 and S. To save time I should omit the evaporation 
of silica to dryness. It is an unnecessary precaution. I pre- 
sume total sulphur can be obtained by a wet oxidation as well 
as a dry one. If the latter is used the crucible should be set in 



MISCELLANEOUS METHODS. 



225 



a hole in asbestos board to keep out sulphur from the gas 
flame. It is just as well to nearly neutralize with ammonia be- 
fore adding barium chloride. 

"H 2 O. Not necessary to mention Penfield's method, 
which is only safe in careful hands, especially when any CO 2 
or sulphides are present/' 

Mr. Clifford Richardson's Scheme for Analysis. These 
suggestions were followed by "a tentative method suggested 
by Mr. Clifford Richardson, for the analysis of limestone, raw 
mixture and Portland cement, proposed for trial by the com- 
mittee and modified in accordance with the suggestions of 
W. F. Hillebrand." 

"Solution. One-half gram of the finely powdered sub- 
stance is to be weighed out, and if a limestone or unburned 
mixture, strongly ignited in a platinum crucible over the blast 
for 15 minutes. It is then transferred to an evaporating dish, 
preferably of platinum for celerity in evaporation, covered with 
a watch glass and 10 c. c. of HC1 diluted with about 50 c. c. of 
water, added. Digestion on the water-bath is allowed to go 
on for about 15 minutes when the substance should be entirely 
decomposed.* The cover glass is then removed, washed and 
evaporated to dryness, as far as this may be possible on the 
bath. 

"Silica. The residue without further heating, is treated 
at first with 5-10 c. c. of strong HC1, and then with as much 
water as the dish will comfortably hold. The cover is then 
replaced and digestion allowed to go on for 10 minuses on the 
bath, after which the solution is filtered and the separated 
silica washed thoroughly with hot water. The filtrate is again 
evaporated to dryness, the residue, without further heating, 
taken up with acid and water and the small amount of silica 
it contains separated on another filter paper. "" The papers con- 
taining the residue are transferred wet to a weighed platinum 
crucible, dried, ignited, first over a Bunsen burner until the 
carbon of the filter is completely consumed, and finally over 
the blast for 30 minutes and checked by a further blasting of 
10 minutes or to constant weight. The silica, if great accuracy 
is desired, is treated in the crucible with about 10 c. c. of HF 

*If anything remains undecomposed it should be separated, fused with 
a little Na 2 CO 3 , dissolved and added to the original solution. 



226 SOLID B/'Ji'.MI-XS. 

and four drops of H 2 SO 4 , and evaporated over a low flame to 
complete dryness. The small residue is washed, finally blasted, 
cooled and weighed. The difference between this weight and 
the weight previously obtained gives the amount of silica.* 

"A1 2 O 3 and Fe 2 O 3 . The filtrate, about 250 c. c., from the 
second evaporation for SiO 2 , is made alkaline with NH 4 OH 
and boiled, to expel excess of NH 3 , or until there is but. a faint 
odor of it, and the precipitated iron and aluminum hydrates, 
after settling, are washed once by decantation and slightly on 
the filter. Setting aside the filtrate, the precipitate is dissolved 
in hot dilute HC1, the solution passing into the beaker in which 
the precipitation was made. The aluminum and iron are then 
reprecipitated by NH 4 OH. The second precipitate is col- 
lected and washed on the same filter used in the first instance. 
The filter paper, with the precipitate, is then placed in a 
weighed platinum crucible, the paper burned off and the pre- 
cipitate ignited and finally blasted 10 minutes, with care to 
prevent reduction, cooled and weighed as A1 2 O 3 + Fe 2 O 3 .f 

"Fe 2 O 3 . The combined iron and aluminum oxides are 
fused in a platinum crucible at a very low temperature with 
about 10 gms. of KHSO 4 , the melt taken up with hot water 
and 25 c. c. of dilute H 2 SO 4 . The clear solution is then di- 
gested on the steam-bath for about 10 minutes, and, if ac- 
curacy is desired, the small amount of silica is filtered out, 
weighed, and corrected by HF and H 2 SO 4 . The filtrate is 
reduced by hydrogen sulphide, boiling out the excess after- 
wards while passing CO 2 through the flask, and titrated with 
permanganate.J 

"CaO. To the comomed filtrate from the A1 2 O 3 + Fe 2 O 3 
precipitate a few drops of NH 4 OH are added, and the solution 
brought to boiling. To the boiling solution 10 c. c. of a sat- 
urated solution of ammonium oxalate is added and the boiling 
continued until the precipitated CaC 2 O 4 assumes a well defined 
granular form. It is allowed to stand for 20 minutes, or until 
the precipitate has settled and is then filtered. The precipitate 
and filter are placed wet in a platinum crucible and the paper 

*For ordinary control work in the plant laboratory, this correction may, 
perhaps, be neglected; the double evaporation never. 

tThis precipitate contains TiO 2 , P2O 6 and MnO. 

Jin this way only is the influence of titanium to be avoided, and a cor- 
rect result obtained for iron. 



MISCELLANEOUS METHODS. 



227 



burned off over a small flame of a Bunsen burner, it is then 
ignited, redissolved in HC1 and the solution made up to about 
100 c. c. with water. Ammonia is added in slight excess, and 
the liquid is boiled. The small amount of A1 2 O 3 is filtered out. 
weighed and the amount added to that found in the first de- 
termination, when great accuracy is desired. The lime is then 
reprecipitated by ammonium oxalate, allowed to stand until 
settled, washed,* weighed as oxide by ignition and blasting 
to constant weight, or determined with standard permanga- 
nate.f. 

"MgO. The combined filtrate from the calcium precipi- 
tates are acidified with HC1 and concentrated on the steam- 
bath to about 150 c. c., 30 c. c. of a saturated solution of 
Na(N HJHPO 4 are added, and the solution transferred to a 
beaker and boiled for several minutes. It is then removed 
from the flame and cooled by placing the beaker in ice water. 
After cooling, NH 4 OH is added drop by drop with constant 
stirring until the crystalline ammonium-magnesium ortho- 
phosphate beginning to form and then in slight excess, the 
stirring being continued for several minutes. It is then set 
aside for several hours in a cool atmosphere and filtered. The 
precipitate is redissolved in hot HC1; the solution made up 
to about 100 cc., 2 cc. of a saturated solution of Na^H^)- 
HPO 4 added and ammonia, drop by drop, wjth constant stir- 
ring until the precipitate is again formed as described. It is 
then allowed to stand for about two hours, when it is filtered 
on paper or a Gooch crucible, cooled and weighed as MgP 2 O 7 . 

"K 2 O and Na 2 O. For the determination of the alkalies, 
the well known method of Prof. J. Lawrence Smith is to be 
followed, either with or without the addition of CaCO 3 with 
the NH 4 C1. 

"SO 3 . One gram of the cement is dissolved in 15 cc. of 
HC1, filtered and the residue washed thoroughly.? 

'The solution is made up to 250 cc. in a beaker and boiled. 
To the boiling solution 10 cc. of a saturated solution of BaCL, 

*The volume of wash water should not be too large, Vide Hillebrand. 
tThe accuracy of this method admits of criticism, but its convenience 
and rapidity demand its insertion. 

JEvaporation to dryness is unnecessary. Vide Hillebrand, 



228 SOLID BITL'MEXS. 

is added slowly, drop by drop, from a pipette and the boiling 
continued until the precipitate is well formed. It is then set 
aside over night, filtered, ignited and weighed as BaSO 4 . 

''Total Sulphur. One gram of material is weighed out in 
a large platinum crucible and fused with NaXCX and a little 
KNO 3 , being careful to avoid contamination from sulphur in 
the gases from the source of heat. The melt is treated in the 
crucible with boiling water and the liquid poured into a tall, 
narrow beaker and more hot water added until the mass is all 
dissolved. The solution is then filtered. The filtrate con- 
tained in a No. 4 beaker is to be acidulated with HC1 and make 
up to about 250 cc. with distilled water, boiled, the sulphur 
precipitated as BaSO 4 and allowed to stand over night. 

"Loss on Ignition. Half a gram of the cement is to be 
weighed out in a platinum crucible, and blasted 15 minutes. 
The loss by weight, which is checked by a second blasting of 
5 minutes, is the loss on ignition." 

At the annual meeting of the American Society of Civil 
Engineers held January 21, 1903, the special committee on 
uniform tests of cement made the following progress report : 

Chemical Analysis. "5. Significance. Chemical analysis 
may render valuable service in the detection of adulteration 
of cement with considerable amounts, of inert material, such as 
slag or ground limestone. It is of use, in determining whether 
certain constituents, believed to be harmful when in excess 
of a certain percentage, as magnesia and sulphuric anhydride, 
are present in inadmissable proportions. While not recom- 
mending a definite limit for these impurities, the committee 
would suggest that the most recent and reliable evidence ap- 
pears to indicate that magnesia to the amount of 5 per cent 
and sulphuric acid to the amount of 1.75 per cent may safely 
be considered harmless. 

"6. The determination of the principal constituents of 
cement, silica, alumina, iron oxide and lime, is not conclusive 
as an indication of quality. Faulty character of cement re- 
sults more frequently from imperfect proportion of the raw ma- 
terial or defective burning than from incorrect proportions of 
the constituents. Cement made from very finely-ground mate- 
rial, and thoroughly burned, may contain much more lime 



M1SCELL. iNEOUS METHODS. 



229 



than the amount usually present and still be perfectly sound. 
On the other hand, cements low in lime may, on account of 
careless preparation of the raw material, be of dangerous char- 
acter. Further, the ash of the fuel used in burning may so 
greatly modify the composition of the product as largely to 
destroy the significance of the results of analysis. 

"7. Method. As a method to be followed for the analysis 
of cement, that proposed by the committee on uniformity in 
the Analysis of Materials for the Portland Cement Industry, 
of the New York Section of the Society of Chemical Industry, 
and published in the Journal of the Society for January 15, 
1902, is recommended." (See page 221.) 

Mr. Bertram Blount's Critique of Mr. Richardson's Re- 
port. In May, 1902, Mr. Bertram Blount of London, Eng- 
land, an eminent English cement expert, read a paper before 
the New York Section of the Society of Chemical Industry, in 
which he "demurred to the methods of the committee on two 
chief grounds : (a) That standardization of strictly analytical 
processes was undesirable ; and (b) that the methods pro- 
posed by the committee were erroneous." 

In the Journal of the American Chemical Society for 
August, 1904, Mr. Blount further discusses the work of Dr. 
Hillebrand and shows that while he finds Dr. Hillebrand and 
himself nearly in accord "there remain a few matters of great 
moment to the manufacturers and users of Portland cement 
and to the chemists who control the quality of their output, 
which are still in doubt ; as the question affects a large indus- 
try and is of much analytical interest it may be usefully dis- 
cussed in detail One of the principal questions as to 

the proper method of analyzing portland cement is that of the 
determination of its insoluble residue The determina- 
tion of insoluble residue is of value because the figure ob- 
tained is an index of the care which has been used in manufac- 
ture ; a cement containing 5 per cent of added sand would be 
diluted to that extent only, whereas one containing 5 per cent 
of insoluble residue is not merely diluted, but has incontesta- 
bly been badly made. The method which I devised and have 
used for nearly twenty years, consists in dissolving the cement 
in hydrochloric acid, evaporating the solution to dryness, but 
not intentionally baking the evaporated material, redissolving 



2 3 

in hydrochloric acid, filtering, washing, dissolving- out the pre- 
cipitated silica with sodium carbonate solution and collecting 
the final insoluble residue. It may be fairly assumed that a 
siliceous residue which has resisted this series of treatments 
is inert and valueless as a cementitious material. I believe I 
am not misinterpreting Dr. Hillebrand when I say that he 
agrees with this ; but he goes further and suggests that the 
treatment is too drastic and that it would be better to deter- 
mine the insoluble residue in such a way that it is not exposed 
to digestion with strong hydrochloric acid. The method he 
proposes is to dissolve in dilute hydrochloric acid, filter at 
once and to remove any precipitated silica by means of sodium 
carbonate. This suggestion is important and has been ex- 
amined in the following manner. Four samples -of cement were 
chosen and the insoluble residue determined in each, both by 
the method which Dr. Hillebrand has proposed and that which 
I 'ordinarily use." 

Dr. Hildebrand. Bertram Blount. 

Per cent. Per cent. Per cent. Per cent. 

1 3.48 3.28 1.10 1.10 

2 3.34 3.12 1.60 1.64 

3 5.20 5.00 1.28 1.36 

4 0.80 0.96 0.50 0.54 

"If we assume with Dr. Hillebrand that the insoluble resi- 
due obtained by his method is inert, evidently the determina- 
tion of this material is of even greater importance than had 
been supposed; it is, however, not easy to obtain conclusive 
evidence on this point. The state of subdivision of the par- 
ticles comprising cement has a great influence on their ac- 
tivity ; unground clinker is scarcely more cementitious than so 
much limestone. Moderately fine particles, on the other hand, 
though setting slowly, will set eventually and it would be rash 
to assume that a material, apparently inert when tested for 
the short period of time generally available in laboratory ex- 
periments, will not prove itself active at long dates, and in 
practice contribute to the strength of the concrete or mortar 
prepared with it. Bearing this in mind, one is not surprised to 
find that the insoluble residue obtained by Dr. Hillebrand's 
method is a cementitious material. This fact was ascertained 
in the following way : The insoluble matter from cement No. 



MISCELLANEOUS METHODS. 231 

i, isolated strictly according to Dr. Hillebrand's prescription, 
was finally ground and then treated again by Dr. Hillebrand's 
own method. The final insoluble residue thus obtained was 
1.52 per cent and 1.66 per cent in duplicate experiments, as 
against a previous mean value of 3.38 per cent on the tin- 
ground substance. In point of fact the retreatment reduces 
the insoluble residue to something closely approaching that 
found by my method of analysis, which, on the same cement, 
gave i.io per cent and 1.16 per cent insoluble residue. It 
would appear from this that the chief difference between the 
two methods arises from the necessity of more finely grinding 
the cement if dilute acid is to be used; when fine grinding is 
substituted for the use of strong acid, similar results are ob- 
tained I thought it possible that this insoluble matter 

might be cementitious. Accordingly a fairly large quantity 
(about 25 gms.) was isolated. This was ground and gauged 
with water after the manner of a cement. As might be pre- 
dicted, it set feebly ; it is, in fact, not a cement per se, but 
rather a pozzuolanic material. Its activity as a pozzuolana 
was proved by gaging it with one-third of its weight of quick- 
lime; it set to a hard mass. As there is always an abundant 
quantity of lime set free from the decomposition of calcium 
silicate and aluminates in the process of the setting of cement, 
capable of acting with a pozzuolanic material, I conclude that 
the insoluble matter, isolated by Dr. Hillebrand's method is 
not inert, but belongs to the cement itself. The insoluble 
residue isolated by my own method is almost wholly silica 
in rather coarse fragments and is substantially inert. On 
these grounds I prefer my original method for determining 
insoluble residue." 

"Next, with regard to the determination of silica in ce- 
ment, Dr. Hillebrand has done excellent service in promoting 
accuracy in mineral analysis by insisting on the necessity of 
double evaporation. I agree that this double evaporation is 
necessary when the silica is set free in a mass of material 
such as is produced when a silicate is fused with sodium car- 
bonate and the melt is decomposed with hydrochloric acid, but 
I consider it is not requisite when the total quantity of ma- 
terial is small and the whole is well baked. It is perfectly 



J-J2 SOLID ttirCMUXS. 

practicable to obtain substantially the whole of the silica from 
Portland cement by a single evaporation." 

"The next matter in which there is a difference of view 
between Dr. Hillebrand and myself (Mr. Blount) is where the 
silica, separated by the ordinary process of solution and evap- 
oration, is pure or contains entangled in or associated with it 
sensible quantities of alumina and other bases." From Mr. 
Blount's experience he concludes that the silica is practically 
pure. He further concludes "that the amount of silica con- 
tained in the ammonia precipitate from cement, analyzed in 
the customary manner, and with only one evaporation for 
silica, is negligibly small." 

And further that, "Experiment has shown that in the 
analysis of cement, silica can be separated by a single evapora- 
tion with a maximum error of 0.32 per cent, and that this 
error is usually smaller; that the amount of silica appearing 
with the ferric oxide and alumina will not exceed 0.14 per cent, 
and is generally less ; that a single precipitation suffices for 
the separation of ferric oxide and alumina from lime and of 
lime from Magnesia." 

In the November, 1904, number of the Chemical Engineer 
appears a 

METHOD FOR ANALYSIS OF PORTLAND CEMENT 
AND CEMENT MATERIALS RECOMMENDED BY 
THE COMMITTEE OF THE LEHIGH VALLEY 
SECTION OF THE AMERICAN CHEMI- 
CAL SOCIETY. 

Cement. "Pass the sample through a loo-mesh sieve to 
free it from clinkers and foreign matter, and keep in a stop- 
pered bottle. Weigh out 0.5 gm. into a wide platinum dish of 
about 50 cc. capcity; add a very little water and break up 
lumps with a glass rod; add 5 cc. hydrochloric acid (i-i) and 
evaporate to dryness at a moderate heat, continuing to heat 
the mass not above 200 C until all odor of acid is gone. 
Do not hurry this baking or skimp the time. The whole suc- 
cess of the analysis depends on thoroughness at this point. 
Cool; add 20 cc. hydrochloric acid (i-i) ; cover, and boil 
gently for ten minutes; add 30 cc. of water, raise to boiling, 



MISCELLANEOUS METHODS. 



233 



and filter off the silica ; wash with hot water four or five times ; 
put in crucible, ignite (using blast for ten minutes) and weigh 
as SiCX." 

The treatment of the solution follows with essentially lit- 
tle difference, betw r een this scheme and those which have pre- 
ceded it. 

The above committee, consisting of W. B. Newberry, R. 
K. Meade and E. B. McCready, prepared a circular letter 
which was sent to thirty chemists of Portland cement works 
and from their replies as well as from the investigations of 
individual members of the committee the method was recom- 
mended. 

Now it is quite clear that the problems presented to a 
chemist in a cement manufactory, and the problems presented 
in a city laboratory, and the problems presented to Dr. Hille- 
brand, are wholly different, and require for their solution con- 
sideration of wholly . different methods of procedure. The 
problems presented to Dr. Hillebrand were wholly scientific 
and have been treated by him in a manner that leaves nothing 
to be desired. While the strictly scientific aspects of the sub- 
ject have been discussed in a masterly and well-nigh exhaus- 
tive manner, resulting in the presentation of a large amount 
of analytical data of the greatest value, the questions have 
been left wholly undetermined whether or no ultimate meth- 
ods of analysis are to be applied indiscriminately to the solu- 
tion of the three classes of problems mentioned above; or, if 
proximate methods are preferable, in what cases are they 
preferable? Those engaged in the manufacture of cement can 
best decide what method of analysis will best solve the prob- 
lems presented to them. So, too, those who use cement and 
those who control the use of cement can best decide what 
methods are best suited to the time, place, conditions and iden- 
tity of the problems presented to them for solution. 

There are a multitude of reasons, too numerous to men- 
tion, why the judgment of Mr. Blount is sound, that each 
chemist should be left free to decide for himself what analy- 
ticl methods he will use, for if the analyst is not capable of 
making this decision, he is like a general in the field subject to 
the dictation of a bureau. 



234 



SOLID BITL'MEXS. 



We have brought together here the most valuable at- 
tempts that have been made within the last eight years to 
bring before the chemists of the country a method of analysis 
that they may all be expected to follow. It is to be presumed 
that as a motive therefor, each of the authors of these several 
schemes was prompted in his work by some ultimate purpose. 
An examination of the schemes show an essential likeness in 
the treatment of the solutions in hydrochloric acid that are ob- 
tained, and at the same time that the methods used in obtain- 
ing these solutions are in no two cases alike, hence it is fairly 
inferred that the motives that prompted the schemes are as 
unlike as the schemes themselves. 

Referring to the scheme of Prof. Henry Carmichael (page 
219), he says: 

"The sample is ground fine in an agate mortar. One gram 
is carefully weighed out in a shallow porcelain dish and well 
covered with a 3 per cent solution of hydrochloric acid. After 
several hours the cement should completely dissolve in this 
acid with the exception of a small mount of sand, mostly 
black cinder, from the fuel employed in making the cement. 
The residue, if any, is filtered off and determined. 

"The clear solution is evaporated to dryness on a water 
bath in a flat dish. Hydrochloric acid is poured over the dry 
residue, and the acid is then evaporated. Add a few drops of 
same acid, again drive off acid. Moisten residue again with 
same acid and boil up with pure water. The silica is rendered 
insoluble by the above operation and can be filtered off and 
weighed. The silica which thus dissolves in the dilute acid, 
and is in turn rendered insoluble, is the silica which is avail- 
able in the setting of the cement. 

Mr. R. L. Humphrey (page 220) says : 

"One-half gram of the finely pulverized sample dried at 
100 C., is thoroughly mixed with four or five times its weight 
of sodium carbonate, and fused in a platinum crucible until 
CO 2 no longer escapes ; the crucible and its contents is placed 
in a beaker, and twenty or thirty times its quantity of water, 
and about 10 cc. of dilute HC1 is added ; when complete solu- 
tion is effected, it is transferred to a casserole and placed on a 
water bath, and evaporated to dryness several times. The 
mass is taken up with dilute HC1 and water, heated for a short 



MISCELLANEOUS METHODS. 235 

time and filtered, washing the residue on the filter thoroughly 
with hot water. The filter is dried, ignited and weighed. The 
weight (less the ash) gives the amount SiO 2 ." 

Dr. Hillebrand (page 222) says : 

"Mode of Attack. Limestone and raw cement mixtures 
should be heated over the blast in order to render them wholly 
soluble and to oxidize sulphides and organic matter. If any 
residue should then remain on treatment with hydrochloric 
acid (with finished cements as well) this should be collected 
without evaporation and fused with a minimum of sodium 
carbonate, its hydrochloric acid solution being added to the 
former." 

Mr. Richardson, for his committee (page 225) says : 

"Solution. One-half gram of the finely powdered sub- 
stance is to be weighed out and, if a limestone or unburned 
mixture, strongly ignited over the blast for 15 minutes. It is 
then transferred to an evaporating dish .... and 10 cc. of 
HC1 diluted with about 50 cc. of water, added. Digestion on 
the water bath is allowed to go on for about 15 minutes when 
the substance should be entirely decomposed." He adds in a 
note, "If anything remains undecomposed it should be sepa- 
rated, fused with a little Na 2 CO 3 , dissolved and added to the 
original solution." 

Mr. Bertram Blount (page 229) says : 

"The method which I devised and have used for nearly 
twenty years, consists in dissolving the cement in hydrochloric 
acid, evaporating the solution to dryness, but not intentionally 
baking the evaporated material, re-dissolving in hydrochloric 
acid, filtering, washing, dissolving out the precipitated silica 
with sodium carbonate solution, and collecting the final insol- 
uble residue. It may be fairly assumed that a siliceous residue 
which has resisted this series of treatments is inert and value- 
less as a cementitious material." 

Finally, we have the method "recommended by the com- 
mittee of the Lehigh Valley section of the American Chemical 
Society" (page 232). The committee says: 

"Pass the sample through a loo-mesh sieve to free it from 
clinker and foreign matter and keep in a stoppered bottle. 
Weigh 'out 0.5 grm. into a wide platinum dish of about 50 cc. 



236 SOLID BITUMENS. 

capacity; add a very little water and break up lumps with a 
glass rod; add 5 c. c. hydrochloric acid (i-i) and evaporate to 
dryness at a moderate heat, continuing to heat the mass not 

above 200 C. until all odor of acid is gone Cool ; add 

20 cc. hydrochloric acid (i-i) ; cover and boil gently for two 
minutes; add 30 cc. of water, raise to boiling and filter off the 
silica; wash with hot water four or five times, put in crucible, 
ignite .... and weigh as SiO 2 ." 

How can uniformity of results be expected to be obtained 
by the use of six fundamentally different methods? These 
schemes are designed for the manufacture of cement to ex- 
hibit the ultimate composition of cements. They are in no 
sense technical. They offer no opportunity for comparative 
results, hence they are of no value in our discussion. We 
shall, however, use them as examples to enforce certain con- 
clusions to which we have been led. 

In addition to these schemes, we wish to call attention to 
correspondence which we have held with a prominent manu- 
facturer of cement, in which he indulged in the following 
criticisms : 

"Experiments we have made show that the solubility of 
commercial portland cements in dilute acid depends greatly 
upon the fineness of grinding. 

"We have found no cements which if ground to extreme 
fineness in an agate mortar, show more than a fraction of i 
per cent of insoluble matter. 

"Since even the monosilicate of lime, Wollastonite. is 
readily decomposed by acid, it is evident that the residue 
should contain practically no lime, and would consist of a 
minute amount of uncombined clay. 

"It is impossible that this should reach more than a frac- 
tion of i per cent in a good cement. 

"Would say further that the use of sufficiently dilute acid 
and fine grinding will give a clear solution without any sepa- 
ration of gelatinous silica. 

To which we replied : 

The first sentence of your letter furnished a key to the 
whole matter. You say: 

"That experiments we have made show that the solubility 



MISCELLANEOUS METHODS. 

of commercial Portland cements in acid depends greatly upon 
the fineness of grinding." 

Believing that this fact as stated by you has been proved 
beyond any question, I insist that every sample of cement 
shall be analyzed in exactly the condition in which it is 
brought to the laboratory; that is, that the specimen shall be 
neither dried nor pulverized, nor in any manner treated in such 
a way as to either lessen or increase the differences that ex- 
ist between the samples as they are brought upon the works or 
are subjected to physical tests. 

I have not yet found a ponderable amount of lime in any 
of the residues from dilute acid that I have examined. 

If you would advocate the uniform grinding of samples 
of cement to an impalpable powder, in an agate mortar, in 
order that they may be more completely dissolved and brought 
into solution, I insist that I do not agree with you. 

I believe that cement of proper fineness for use is soluble 
in 10 per cent hydrochloric acid (iHCl. sp. gr. 1.2 tog~H. 2 O), 
without gelatinization, and that any matter not so soluble, 
contained in commercial cement, is not cement at all, and is, 
and should be classed as "inert matter." 

To which he replied : 

"Your separation of the constituents of cement by the 
action of 10 per cent hydrochloric acid on the commercial 
cements, appears to me to be without foundation. 

"The varying amounts of insoluble matter obtained by 
you on treating the same cement with acid of varying 
strengths and in various ways appears to show that the 
amount of insoluble matter depends upon the method em- 
ployed, rather than upon the chemical character of the cement 
analyzed. 

"I have found that most commercial Portland cements, if 
ground to great fineness, give scarcely any insoluble residue 
on treatment with sufficient quantity of 5 per cent acid. 

"The high percentage of insoluble matter obtained by you 
simply results from the comparatively coarse grinding of the 
cement. 

"You certainly will not contend that the composition of 
the coarser particles is materially different from that of the 
fine ones, or that the chemical character of the cement is 



SOLID Bl'l l'ME^S. 

changed by grinding the coarse particles to uniform fineness 
with the rest. 

"Your choice of 10 per cent acid and method of mixing 
appear to me to be wholly arbitrary, and the conclusion drawn 
from the amount of insoluble matter obtained to be quite 
unjustified. 

"Since coarsely ground cement gives a considerable 
residue when treated with dilute acid, while finely ground 
cement gives practically none, and since this residue consists 
chiefly of silica, and contains, as stated by you, practically no 
lime, it appears to me evident that this insoluble matter re- 
sults chiefly from local separation of silica contained in the 
coarse particles. 

"The lime and other constituents contained in these par- 
ticles, are, however, dissolved, and are included by you in 
the group of active constituents. 

"The injustice of this is apparent. 

"If the silica of the coarse particles is inactive, the lime 
must be so also. 

"It is undoubtedly correct to submit commercial sam- 
ples of cement to physical tests as they are received, without 
grinding. 

"To submit these samples to chemical analysis, however, 
without bringing them into homogeneous condition by grind- 
ing, is certain to lead to erroneous conclusions. 

"In burning, however, a disturbing factor enters, and this 
is the ash of the coal dust used as fuel. 

"This ash adds at least 2 per cent to the silica, alumina 
and iron oxide of the product. 

"It is, however, brought into combination with the lime 
of the charge sufficiently to become wholly soluble in acid, 
but not uniformly enough to allow the lime of the raw mate- 
rial to be raised to a corresponding extent. 

"I believe fully that the best Portland cements are thor- 
oughly homogeneous in character, and that the excess of 
silica, alumina and iron over that called for by the formula is 
due to the ash of the fuel and to the general practice of carry- 
ing the lime a little below the maximum in order to offset pos- 
sible fluctuations in the mixture." 



239 

I asked my correspondent to send me a sample of the 
fuel ash. 

He replied : 

"It will be impossible to send you a sample of the coal ash 
to which you refer, as this melts in with the clinker with which 
it comes in contact in the rotary kilns. 

"The amount of fuel used is about 150 Ibs. to the barrel 
of cement. 

'The ash of this fuel is about 8 per cent, and if all ab- 
sorbed by the clinker would add about 3 per cent of silica, iron 
and alumina to the latter." 

The absolute worthlessness of an ultimate analysis of 
cements, cement mortar and concretes was forcibly brought 
to my attention at the outset of my investigation of this sub- 
ject. No one disputes that a cement that has not been dam- 
aged by exposure is brought upon the works and is made into 
mortar and concrete, substantially, just as it leaves the manu- 
factory. In this condition it is subjected to physical tests. The 
fineness of its grinding is one of the properties that materially 
affects the results of physical tests. These tests are also, to 
s'ome extent, determined by the amount and kind of material 
that is not cement that is accidentally, carelessly or purposely 
mingled with the cement, or that results from the inevitable 
defects of a technical process of manufacture that is only ap- 
proximately perfect. 

No one who was about to apply physical tests to a sam< 
pie of cement brought from work in progress, would sift the 
sample through a loo-mesh sieve to remove "clinker and for- 
eign matter," nor would he pulverize it to improve its cohesive 
strength, nor dry it to remove water that may have been ab- 
sorbed. The cement goes into the mortar and concrete as it is 
received upon the work in progress, with all of the sand, ashes, 
unburned slurry, over-burned slurry, unburned cement rock 
and other "foreign matter" that it may contain, and with all 
the imperfections of grinding; in fact, with all the qualities 
good and bad, which it may possess. To attempt to remedy 
or supplement any defects possessed by the sample before 
applying the physical tests would make those tests a farce as a 
means of determining the qualities of the cement in actual use. 
Why is it any less a farce to conduct a chemical examination 



240 SOLID BITUMENS. 

in such a manner as to improve the qualities of the sample 
by supplementary grinding or by sifting out the "clinker 
and foreign matter;" or by adding the silica of the sand and 
ashes to the silica of the cement by fusion with Na 2 CO 3 , or by 
the action of concentrated HC1; or, by the same means add- 
ing the alumina and iron of the ashes to the alumina and iron 
of the cement. To expect correlation under such conditions 
is the most complete unreason. 

The requirements of the problem demand that whereas, 
the same substance as it leaves the manufactory is made into 
mortar and concrete and is subjected to physical tests, the 
same substance shall be subjected to chemical tests and in 
such manner that the identity of the substance shall not be 
lost or subjected to change at any step in the progress of 
.such tests. 

In the determination of what this manner shall be the 
question arises, "What is cement," from a technical stand- 
point? The question is answered, it is a pulverized material 
that when mixed with water under certain conditions de- 
velops hydraulic properties and cohesive strength. The 
primary consideration is, permanent cohesive strength when 
mixed with sand as mortar and with sand and stone as con- 
crete. 

The constitution of cements has been under discussion 
for many years, but no results approaching finality may be 
said to have been reached until those described by the Messrs. 
Xewberry were published in 1897. It is not necessary here to 
review the work of Le Chatelier and Vicat. That work has 
been sufficiently well done by the Messrs. Newberry in their 
several papers. I wish, however, to re-state the Newberry's 
results in order to point out their relation to the present work. 

The Newberrys have shown, by the most elaborate and 
conclusive physical and chemical tests, that the formula for 
cements is "% lime = 2.8 (% silica) + i.i (% alumina)." 
They have further shown that in the manufacture of cement, 
alumina and iron may be taken together, while magnesia is 
inert, and sulphuric oxide and the alkalies in small quantity 
may be disregarded. From all of which it is fair to conclude 
that the lime, soluble silica, iron and alumina are the constitu- 



MISCELLANEOUS METHODS. 241 

ents of a cement that give it value, while all the other constitu- 
ents that it may contain are inert or injurious. 

It may therefore be assumed that a perfect theoretical 
cement, formed synthetically from pure materials, would be 
found upon analysis to be represented by the formula 

Ca 
i 

2.8 Soluble Silica + i.i Alumina and Iron Oxides 

No cement, either Portland or Rosendale or slag, on the 
market, consists of chemically pure hydraulic cement. A 
commercial Portland cement therefore consists of the above- 
named compound, plus, not a trace, but an unavoidable per- 
centage of the ashes of the coal employed as fuel, also of over- 
burned and under-burned clinker, also of uncombined clay, 
magnesia, sulphuric oxide, alkalies, water and carbonic oxide 
(COo). In cements of good quality those percentages are 
small ; but in cements that are poorly prepared or purposely 
adulterated they are varyingly larger. 

In the case of natural cements, there is in addition to 
those above mentioned, an unavoidable percentage of both 
over-burned and under-burned cement rock, particularly the 
latter, together with more or less minute fragments of the fuel 
used that are ground up with the cement. 

It is assumed that these impurities are unavoidable, be- 
cause from the nature of the case no cement^can be manufac- 
tured without some of them and no cement that I have 
examined has been entirely free from all of them. While in 
cements of good quality the percentages are individually 
small, they are in the aggregate sufficient to be an element 
affecting quality that must always be reckoned with when any 
attempt is made to correlate the results of chemical analysis 
with physical tests. 

As the Newberrys have demonstrated that the lime, solu- 
ble silica, alumina and iron are the constituents of a cement 
that give it value, and further, that whatever the chemical 
compounds may be that exist in cement the elements are em- 
pirically combined in the percentage relations represented by 
the above formula, Newberry's formula becomes empirically 
of great technical value, as furnishing a means of compar^on 
by which through chemical analysis the varying qualities of 



242 SOLID BITUMENS. 

cements as demonstrated by physical tests, may be explained. 

It then becomes of the greatest importance that a method 
of analysis be followed that would clearly separate the 
cement, which more or less closely approximates in empirical 
composition Newberry's formula, from the various substances, 
noxious and inert, with which it may be associated, that are 
not cement. It is along this line of investigation that the in- 
terests of engineers, and others who control the use of cement, 
are wholly to be found. It is therefore with surprise that one 
reads from the progress report of the Special Committee on 
Uniform Tests of Cement of the American Society of Civil 
Engineers, that "the determination of the principal constitu- 
ents of cement silica, alumina, iron oxide and lime is riot 
conclusive as an indication of quality. The ash of the fuel 
used in burning may so greatly modify the composition of 
the product as largely to destroy the significance of the results 
of analysis/' This surprise vanishes when it is found that 
Mr. Richardson's scheme of analysis as proposed by the Com- 
mittee on Uniformity in the Analysis of materials for the 
Portland Cement Industry of the New York Section of the 
Society of Chemical Industry (page 225) is recommended. 

This scheme begins by finely pulverizing the sample and 
then pouring upon it 10 c. c. HC1 diluted with about 50 c. c. 
of water. "If anything remains undecomposed it should 'be 
separated, fused with a little Na 2 CO 3 , dissolved and added to 
the original solution." This is a method of ultimate analysis. 
It is no better than Humphrey's method which starts out with 
fusing the whole sample with Na 2 CO 3 . By this method any 
distinction between the part which is cement and the part 
which is not cement is impossible. All of the silica, whether 
sand, ash or soluble silica, is weighed in one mass and called 
SiO 2 , and means nothing, as only the soluble silica has any 
value as a constituent of cement. So too, the alumina and 
iron that belong to the cement that is present, is mingled with 
the alumina and iron that form a part of all the material that 
together constitutes the not cement. This committee has given 
directions for physical tests that are clear, but the suggestions 
relating to the chemical analysis are vague, inconclusive and 
practically worthless. The value of a chemical analysis of 
cement depends absolutely upon how it is conducted, and may 



MISCELLANEOUS METHODS. 243 

either wholly confirm and explain the physical tests or be 
wholly worthless for any purpose. Mr. Blount is perfectly 
correct when he characterizes this scheme as "erroneous." 

Nor is Mr. Blount's scheme, which he has used so long, 
any less "erroneous." He dissolves "the cement (presum- 
ably as received) in hydrochloric acid (presumably concen- 
trated), evaporating the solution to dry ness, but not inten- 
tionally baking the evaporated material, redissolving in hy- 
drochloric acid, filtering, washing, dissolving out the precipi- 
tated silica with sodium carbonate solution and collecting the 
final insoluble residue." He thinks "it may be fairly assumed 
that a siliceous residue, which has resisted this series of treat- 
ments, is inert and valueless as a cementitious material." 
With this assumption we fully agree, but, why should he as- 
sume that material that did not resist this series of treatments 
is all cement? 

It may be that cements burned in briquettes are free 
from admixture with materials that are not cement, and that 
will not resist such treatment, but cements burned in rotary 
kilns contain the ashes of the fuel, which will not resist the 
action of even cold concentrated hydrochloric acid. My cor- 
respondent (page 236) says he cannot add such an excess of 
lime, as, when combined with the alumina and silica of this 
ash would make cement, because it will not so combine. The 
lime remains free and in excess and injures tke cement, while 
the ash remains free and mechanically mingled with the ce- 
ment both in the clinker and when ground. These ashes are 
decomposed either by fusion or by strong hydrochloric acid, 
and the constituents are improperly added to those of the 
cement. 

If an ultimate analysis is desired, by all means use the 
scheme presented by Mr. Richardson's Committee, a scheme 
that is well nigh perfect. But excellent as it is, it is not suited 
to the work in hand, and it is therefore concluded that while 
the practical value of the labors of Mr. Blount, Dr. Hillebrand 
and Mr. Richardson's Committee cannot be over-estimated, it 
is quite clear that the problems presented to a chemist in a 
cement manufactory, and the problems presented to engineers 
and the users of cement generally, and the problems presented 
to Dr. Hillebrand are wholly different and require for their so- 



244 SOLID BITUMENS. 

lution consideration of wholly different methods of procedure. 

Those engaged in the manufacture of cement can best 
decide what method of analysis will best solve the problems 
presented to them. It is evident from the reports above cited 
that they have decided they require an ultimate analysis. It 
is not clear to us in what respect the method promulgated by 
the Committee of the Lehigh Valley section of the American 
Chemical Society, is superior to the method proposed by Mr. 
Richardson's Committee, which, as before stated, seems to us 
as a method of ultimate analysis, well night perfect. 

So, too, those who use cement and those who control the 
use of cement can best decide what methods are best suited 
to the time, place, conditions and identity of the problems pre- 
sented to them for solution, and it is to these problems that 
\ve now address ourselves. We find that the users of cement 
have not been represented on the committees that have de- 
vised these schemes, nor heard in their reports, hence the 
necessity for giving their problems due consideration. 

The Method of Analysis. As before stated, the cement 
is used upon the work in progress as it is received from the 
manufactory. It is subjected to physical tests as it is used 
upon the work in progress. It should be subjected to chem- 
ical analysis as it is used upon the work in progress. It 
should neither be dried, pulverized noi sifted, because to dry, 
pulverize or sift it would convert it into a different sample 
that was not a sample of the cement used upon the work in 
progress or subjected to physical tests. Moreover, it would 
be impossible to dry, pulverize or sift the cement that had 
already been put into cement mortar or concrete, hence a 
scheme designed to correlate the results of physical tests with 
the chemical examination of cements, cement mortars and 
concretes, must, so far as is possible, require that the sample 
of cement used shall preserve its identity through all of the 
various tests. It is therefore imperative that the physical and 
chemical tests shall be made upon the sample just as received 
and that the mortar and concretes shall be slowly dried at a 
temperature not to exceed 220 F. in such manner as not to 
remove any of the combined water. An electrical oven that 
will maintain a uniform temperature of 220 F. for an in- 
definite period, is used for this purpose. 



MISCELLANEOUS METHODS. 24$ 

Having dried the mortar or concrete at a uniform tem- 
perature, the mortar is carefully separated from the stone and 
each weighed. The proportion of stone to mortar is thus 
determined. The mortar is then sifted through a No. 10 sieve 
to remove the gravel. This has to be done in order to secure 
an accurate weighing of an average sample. Sand used for 
concrete is seldom, if ever, screened and the mortar therefore 
contains a certain percentage of gravel that can only be de- 
termined accurately in a larger sample than can be used for 
analysis, hence it must be separated and at the same time 
weighed and included as a part of the sand. 

(1) Volatile at a Red Heat. The first step in the proc- 
ess of analysis is to determine the amount volatile at a red 
heat. The temperature should be sufficient to expel the car- 
bonic oxide and combined water, but should not be high 
enough to sinter the assay. Mr. Richardson recommends a 
blast lamp. We think that a three-tube Bunsen burner is 
amply sufficient, but a single tube Bunsen is not. An elec- 
trical muffle that can be adjusted to a low red heat is superior 
to anything we have ever used. With two small platinum 
crucibles, duplicate determinations can be made on I gm. of 
cement each, or 2 gms. of mortar, at precisely the same tem- 
perature and with great accuracy. The loss is combined 
water and carbonic oxide (CO 2 ) with a small amount of mois- 
ture in some cements. 

(2) The Sample. Five gms. of the cement or 10 gms. of 
the mortar are carefully weighed out. Of course, if the ce- 
ment is reduced to an impalpable powder by supplementary 
grinding, a fair average may be obtained in 0.5 gm. So too, 
if all cements that are to be analyzed are first class, a fair 
average may be had in 0.5 gm. ; but, a large part, if not the 
major part of the cements analyzed are of inferior quality, 
hence a sufficiently large sample should be weighed out to 
ensure a fair average mixture of the cement with that which 
is not cement. In the case of mortars when sand in large 
amount has been mixed with the cement, the necessity for a 
large sample is obvious. 

(3) The Solution. When analytical work was first un- 
dertaken several years ago, I found, in common with others 



246 SOLID BITUMENS. 

who attempted to correlate the physical and chemical tests, 
that no correspondence could be observed. 

Believing that Nature could not contradict herself, I was 
convinced that there must be some defect in the question put 
to nature, in the chemical analyses ; in other words, that the 
chemical analysis was not properly conducted. This led to 
the conclusion that the purpose of an analysis was not satis- 
fied when a method of ultimate analysis, in some respects, in- 
adequate, was followed. I therefore sought to arrange a 
method of analysis that should be proximate. I observed that 
when concentrated HC1 was poured upon a portion of cement 
in an evaporating dish the reaction w r as very violent with 
evolution of heat that was perceptible on the outside of the 
dish. It was also apparent that much of the combined silica 
was separated and rendered insoluble, and thus became 
mingled with the sand and insoluble residue. It appeared 
that the combined silica should be kept in solution, if possible, 
and separated by filtration from the insoluble portion. To do 
this in an effective manner led to a series of experiments in 
which the attempt was made to first dissolve the lime and 
other basic elements in combination with CO 2 as carbonates, 
before decomposing the silicates. A dozen different acids of 
varying strength were tried all of which decomposed indif- 
ferently both carbonates and silicates, and all attempts in this 
direction were abandoned. A 20 per cent acid (iHCl, sp. gr. 
1.2 to 4 H 2 O), was then used, which was poured upon 5 gms. 
of the cement in a casserole, the results being given as No. 
I in table. The results appearing as No. II were ob- 
tained when the cement was carefully and slowly jarred upon 
the same acid. Another analysis was made by pouring con- 
centrated acid upon the cement, with results given as No. III. 
Still another was made by pouring upon the cement 10 per 
cent acid, with still other results given as No. IV. A study 
of these results led to the suggestion that possibly the active 
chemism attending the solution in the several instances ob- 
served might be responsible for the varying results. 

Five gms. were then sifted through a No. 40 sieve upon 
the surface of 250 c. c. of 10 per cent acid in a No. 8 evaporat- 
ing dish in such a manner as to reduce the evolution of heat 



MISCELLANEOUS METHODS. 247 

to the lowest terms and thus keep in solution all of the com- 
bined silica that is set free. 

The mixture was then vigorously stirred at intervals for 
half an hour, or until all that would dissolve was in solution, 
when the solution was filtered and the residue on the filter 
thoroughly washed with hot water. The results obtained are 
given as No. V. Assuming that the magnesia, sulphuric 
oxide and loss at a red heat were correctly estimated in No. 
I, Nos. IV and V give, respectively, a total of 99.20 per cent 
and 99.21 per cent. There is a very little difference in the 
percentages of lime, but the sieve method yields the largest 
percentage of soluble silica. It was inferred from this result 
that perhaps a still weaker acid might dissolve more silica, 
and the attempt was made to decompose the cement with a 
5 per cent acid, but without success. 



No. 



I 


JS ^> 

.HE 
"o 

(/} 

20 42 


12.24 


7.50 


o 

3 

55.05 


<L> 

c 
bfl 

2.19 


*O 

C/5 

1.90 


rt o 

C/3 ^ 

O 

1.15 


J.S 
5.27 


'g ^ 
0.52 


11 


7.87 


16.37 


8.88 


62.32 


2.19 


1.90 


1.15 


5.27 


0.52 


III 


2239 


1.63 


8.98 


62.74 


2.19 


1.90 


1.15 






IV 


5.83 


17.37 


9.00 


61.76 


2.19 


1.90- 


1.15 


5.27 


0.52 


V 


5.79 


17.81 


8.65 


61.72 


2.19 


1.90 


1.15 




0.52 



The 10 per cent acid used in this work, and hereafter re- 
ferred to as 10 per cent HC1, is not a solution of HC1 contain- 
ing 10 per cent by weight of dry HC1 gas, but is a solution of 
HC1 made by diluting one part concentrated HC1, sp. gr. 1.2, 
with nine parts distilled water, containing between 4 and 5 
per cent of dry HC1 and having a sp. gr. of about 1.02. Acid 
of even this degree of dilution if poured upon dry cement will 
produce sufficient heat at the point of contact to convert a 
portion of the silica into an insoluble form. If, however, the 
directions here given are followed the silica all remains in 
solution and nothing but the cement is decomposed ; 250 c. c. 
of this 10 per cent acid contains 25 c. c. of concentrated hydro- 
chloric acid, which is equal to about 10 gms. of dry HC1 gas, 
which, in practice, has been found sufficient for the purpose. 



248 SOLID BITUMENS. 

In the analysis of cement mortars the cement used is di- 
luted with a large amount of quartz sand. In an examination 
of any given specimen of cement mortar, the portion of the 
sand soluble in 10 per cent HC1, while small, should be de- 
termined if possible, in a separate sample of the sand used in 
the mortar, and the result obtained, used in correcting the 
results obtained from the analysis of the mortar. Ten gms. 
of the mortar are weighed out and treated as if it were cement, 
by slowly jarring it on to the surface of 250 c. c. of the 10 per 
cent acid contained in a No. 8 evaporating dish. The acid 
should not be heated and the solution should not be hurried 
as the slow solution of the cement with little or no* rise of 
temperature is essential to the complete solution of the soluble 
silica and at the same time the complete separation of the 
cement from the sand and other materials that are not cement. 

Concerning this solution of either cements or mortars it 
is to be remarked, that the sample taken for analysis being 
identical with the sample selected for physical tests and so 
treated as not to change its chemical relations to the solvent 
used, the material treated is separated into the cement which 
passes into solution and that which is not cement which re- 
mains undissolved. 

If effervescence follows it indicates the presence of car- 
bonic acid. Traces of H 2 S are to be expected. A black resi- 
due indicates carbon or soot, which may be estimated by gath- 
ering the residue on a balanced filter, weighing, burning off 
the carbon and again weighing. Neither carbonic acid, car- 
bon nor soot are to be expected in first class Portland ce- 
ments. More or less CO 2 is usually present in natural cement. 
Coal appears to be sometimes ground with cement to change 
its color. 

(4) The Residue. Our correspondent furnished us a 
sample of the coal he was using. Analyzed, it yielded 11.95 
and 11.76 per cent of ash, an average of 11.85 per cent which 
at 380 pounds of cement to the barrel, equaled 4.68 per cent 
of ash instead of 3 per cent. Of this ash 22.92 per cent was 
soluble in 10 per cent hydrochloric acid. 



MISCELLANEOUS METHODS. 249 

The ash consisted of : 

Silica 42.94 per cent. 

Alumina and ferric oxides 41.41 " 

Lime (CaO) 9.52 

Sulphuric oxide SO 3 3.58 " 

Undetermined 2.55 " 

100.00 per cent. 

The sulphuric oxide was wholly soluble in dilute hydro- 
chloric acid. 

Another sample of coal yielded 10.63 P er cent of ash, 
which is equal to 4.2 per cent of ash in the clinker. When an- 
alyzed this ash yielded : 

Silica 43.30 per cent. 

Alumina and ferric oxide 38.69 " 

Lime 9.12 

91.11 per cent. 

There was undetermined SO 3 , CO 2 and a trace of H 2 S. 

This analysis, as well as the one given above, seems to in- 
dicate that the lime in the fuel ash combines to form a soluble 
compound with a part of the silica, alumina and iron, while 
the remainder of the silica, alumina and iron, being in excess, 
still continues in combination in a form not readily decom- 
posed by dilute acids, although easily attacked by concen- 
trated acids. 

This explains why some of the very best cements are 
gelatinized with only a little more than a trace of matter un- 
decomposed by concentrated acids and yield a residue to 
dilute acid having the appearance of ashes, but containing no 
lime, and less in amount than the ash contained in the coal 
used, as is shown in the analytical results given above. 

When an attempt is made to make a chemical examina- 
tion of cement mortars and concretes the impossibility of 
using an ultimate method is at once obvious. The average 
specimen of quartz sand is nearly or quite inert to the action 
of 10 per cent HC1. Acid of this strength therefore will dis- 
solve the cement and leave the inert sand when a sample of 
cement mortar is under examination. With this acid the 
character of the cement becomes at once apparent. If carbon 



250 SOLID BITl'MllXS. 

or carbonic acid are present, they are at once set free. If un- 
burned cement rock has been ground with the cement, the 
excessive amount of fine insoluble material in the sand is at 
once discovered. With a first class Portland cement and clean 
sand, the residue from the solvent is found to be almost 
wholly clean sand. 

The cement in the cement mortar or concrete must be the 
same as that which was used in the work in progress, from 
which the sample of mortar or concrete was taken. It must 
be the same as that subjected to physical tests. It can neither 
be dried, pulverized nor sifted to remove clinker and other for- 
eign matter. It must be taken with all of its properties, good 
and bad. It is imperative that it should be analyzed by pre- 
cisely the same method that is followed in the analysis of the 
cement. 

A portion of the cement, as it is brought in from the work 
in progress is subjected to physical tests. Another portion of 
the cement just as it is brought in, is subjected to chemical 
analysis. Frequently the broken mortar briquettes are sub- 
jected to analysis. Frequently also, portions of cement con- 
crete are brought in from the works. These are broken up, 
the mortar separated from the stone and both dried at a tem- 
perature not to exceed 220 F. and weighed. As the mortar 
consists of about 70 per cent sand, 10 gms. are weighed out 
in pieces, free from dust, and large enough to secure an aver- 
age, which at the same time shall be free from pebbles of 
gravel. Either 5 gms. of this cement or 10 gms. of the mortar 
are placed in 250 c. c. of 10 per cent hydrochloric acid, and, 
after standing several hours, or over night, the insoluble resi- 
due is separated by filtration, dried, ignited and weighed. 

If an analysis of this residue is desired, it is fused with 
Na 2 CO 3 , the melt dissolved in 10 per cent HC1 and water, 
the silica separated and the solution proceeded with sepa- 
rately, according to the following scheme. 

(5) Silica. If extreme accuracy is desired, the method 
described by Dr. Hillebrand beginning with (3) Separations, 
(p. 222) is recommended ; or, if it is preferred, the scheme of 
Mr. Richardson (page 225), beginning at the "filtrate is again 
evaporated to dryness" under "Silica," may be employed. 



MISCELLA NEO US ME TIIODS. 



251 



For ordinary technical analysis the double evaporation 
of the solution from 5 gms. is not necessary. 

The filtrate from the solution in 10 per cent HC1, with 
the washings are evaporated in a No. 8 evaporating dish over 
a water bath. A large dish is selected in order that the residue 
from evaporation may be spread out in a thin layer over a 
large surface. The silica solution is evaporated over night 
over a water-bath heated by an electrical stove. Morning 
usually finds the residue dry at a temperature below the boil- 
ing point of water. Heating to a temperature of about 250 
F., on an electrical stove completes the dehydration at a uni- 
form and low temperature. 

The dried residue, distributed in a thin layer upon the 
bottom of the evaporating dish, is drenched with concentrated 
HC1, care being taken that every particle of the residue be 
wetted with the acid. The iron will all pass into solution if 
the baking has been conducted with care and is not excessive. 
The excess of HC1 is evaporated, the residue wetted with con- 
centrated HC1 and about 300 c. c. of distilled water added. 
The solution is then boiled, filtered hot and the precipitated 
silica thoroughly washed with boiling distilled water. I am 
not prepared to say that small quantities of silica' do not re- 
main in solution on a single evaporation, but for technical 
purposes it is a negligible proportion of that contained in 5 
gms., when evaporated and dried as here directed. The silica 
is then ignited and weighed without blasting, the errors being 
practically "compensating errors." 

(6) Alumina and Ferric Oxide. The filtrate from the 
silica with the washings is poured into a graduated liter flask 
and the solution made up to one liter. After thorough agita- 
tion, two portions of 100 c. c. each, are placed in two beakers, 
ammonium hydroxide added in slight excess and about 150 
c. c. of distilled water. The excess of ammonia is boiled off 
and the precipitated alumina and ferric oxide is gathered on a 
filter. The receptacle for the filtrate is removed, the filter 
filled with 10 per cent HC1 and as it passes through the filter 
is received into the first beaker and any precipitate adhering 
to the sides is dissolved off. By proceeding in this manner 
the whole of the alumina and iron is again brought into solu- 



252 SOLID BITL'MEXS. 

tion ; ammonia is again added and the precipitate is again 
brought upon the filter, the filtrate being added to that first 
obtained. As the amount of cement contained in the original 
loo c. c. of solution is only 0.5 gm., the alumina and ferric 
oxide is rarely sufficient in amount to admit of its being re- 
moved from the filter. After being thoroughly washed in boil- 
ing water it is dried and burned at a low red heat and weighed. 
If this procedure is followed with reasonable care the amount 
of iron reduced from the peroxide will be insignificant. 

(7) Lime. The united filtrates from the alumina and 
iron is then heated to boiling and a slight excess of a sat- 
urated solution of ammonium oxalate is added and the boiling 
continued until the precipitate becomes granular. It is well 
to set the beaker away over night. It should stand at rest at 
least two hours, when the precipitate is collected on a filter 
and washed with very dilute ammonium hydroxide. The 
dried precipitate is ignited, the paper burned off over .a Bun- 
sen lamp, when the crucible is placed over a blast and blasted 
15 minutes. The CaO is then cooled and weighed. 

(8) Magnesia. The filtrate from the CaO is rendered 
acid with HC1 and evaporated on the steam bath to about 150 
c. c., 30 c. c. of a saturated solution of Na(NH 4 )HPO 4 are 
added and the solution boiled for a few minutes, and cooled 
by placing the beaker in cold water. After cooling, NH 4 OH 
is added cautiously with constant stirring, avoiding more than 
a slight excess until the crystalline precipitate begins to form. 
The stirring is then continued for several minutes, after which 
it is set aside for several hours or all night in a cool place, 
after which it is filtered. If, as will be found in the majority 
of instances, the precipitate is a trace or but little more than 
a trace, the filter containing the precipitate is burned off and 
thoroughly blasted, cooled and weighed. If the precipitate is 
of considerable amount, it is redissolved in hot dilute HC1, 
the solution made up to about 100 c. c., 2 c. c. of a saturated 
solution of Na(NHJHPO 4 and NH 4 OH, added separately, 
drop by drop, with constant stirring until the precipitate is 
again formed. It is then allowed to stand at least two hours 
in a cool place, filtered, blasted, cooled and weighed as 
MgP 2 7 . 



MISCELLANEOUS METHODS. 253 

For technical purposes the lime and magnesia are easily 
determined with one precipitation each, although each may be 
contaminated with a trace of the other. 

(9) Sulphuric Oxide. For sulphuric oxide, two por- 
tions of loo c. c. each are taken from the solution left in the 
liter flask from which the silica has been removed. These 
portions in a beaker glass are heated to boiling and 10 c. c. of 
a saturated solution of BaCl 2 are added, drop by drop, from a 
pipette, and the boiling continued until the precipitate has 
formed, when it is set aside over night. It is then filtered, 
ignited and weighed. 

If a determination of total sulphur is required the method 
followed by Mr. Richardson's Committee is recommended. 
(Page 228.) 

(10) Alkalies. It is rare that for technical purposes a 
determination of carbon dioxide or alkalies is necessary. The 
recommendation of Mr. Richardson's Committee that "the 
well known method of Prof. J. Lawrence Smith is to be fol- 
lowed, either with or without the addition of CaCO 3 with the 
NH 4 C1, cannot be improved. 

(n) Carbon Dioxide. If a determination of CO 2 is 
desired any one of the many approved methods and apparatus 
devised for that purpose is recommended. 

While we are aware that sometimes for special reasons, a 
very elaborate and accurate analytical examination of a sam- 
ple of cement is desirable, such an examination is seldom or 
never required for cement mortars. For the purposes under 
discussion the following named determinations have been re- 
peatedly demonstrated as furnishing all of the data necessary 
for a correlative examination of cements, cement mortars and 
concretes : 

(1) Matter volatile at a red heat. 

(2) Matter insoluble in 10 per cent HC1. 

(3) Soluble silica. 

(4) Alumina and ferric oxide. 

(5) Lime. 

(6) Magnesia. 

(7) Sulphuric oxide. 



-'54 



SOLID Bl'l L'MEXS. 



It is not necessary that analytical methods furnishing re- 
sults accurate to a thousandth of a per cent, should be fol- 
lowed, because it is not possible to use samples that agree 
with each other to any such degree of parallelism. This state- 
ment should not, however, be understood as being regardless 
of accuracy, which is at all times to be held as the corner- 
stone of effective analytical work. Yet, while accuracy is 
never to be lost sight of, the time required to obtain results of 
practical value is a very potent factor in all technical opera- 
tions and it is constantly forcing a compromise between ac- 
curacy regardless of tim/: and speedy results obtained regard- 
less of accuracy. In the interest of such a compromise we 
have recommended the scheme as above stated. 

In order to further test the value of this scheme as fur- 
nishing results correlative with physical tests, four samples of 
cement were selected and numbered. 

No. 77oa was a strictly first class American Portland 
cement. 

No. 7713 was a so-called "improved" cement alleged to 
have been made by mixing 77oa with a natural cement. 

No. 774a was another good American Portland cement. 

No. 775a was another "improved" cement made by mix- 
ing 774a with a natural cement. 

These four cements were made into mortars with stand- 
ard quartz in the proportion of one part of cement and three 
parts of quartz by weight. 

The cements were made into briquettes neat and the mor- 
tars were also made into briquetts. All of these briquettes 
were broken in two series, one of seven days and the other 
of twenty-eight days. The cements and broken briquettes 
were analyzed according to the scheme above set forth. 

The silica was determined with and without blasting and 
with a second evaporation. The amount of silica obtained 
from the second evaporation varied from o.n to 0.55 per cent. 
The amount depends entirely upon the care that is exercised 
in the first evaporation. With complete burning over a three 
tube Bunsen lamp the reduction of weight by blasting was 



MISCELLANEOUS METHODS. 



255 



o.i per cent, and with careful manipulation the amount ob- 
tained by a second evaporation was o.n per cent. These 
sources of error compensate each other and while they are 
errors, they are of no account in a technical analysis. No 
reckoning can be made with careless manipulation. Careless 
manipulation was purposely indulged for the purpose of ob- 
serving its effects. These effects are fully exhibited in the 
table given below. 

The great value of chemical analysis when properly con- 
ducted for the explanation of physical tests, when applied 
both to cements and mortars and the complete correlation of 
such analyses with such tests are clearly and emphatically set 
forth in the results exhibited in the table. 

CHEMICAL ANALYSES. 

NEAT CEMENTS. 



Average 
of seven 
Samples of 
American 


Portland 


Laboratory Number. 


770a. 


774a. 


771a. 


775a. 


Cement. 


Volatile at a red heat, per cent 


0.65 


2.80 


6.55 


7.72 


1.79 


Insoluble in 10 per cent HC1. . . . 


3.63 


5.68 


8.16 


10.31 


4.38 


Effervescence observed 


none 


none 


none 


none 


tinno 


Carbon observed 


none 


trace 


1.93 


coal 


UUUv 

finti> 


Soluble silica, 1st evaporation, 








IAMU 


iiuiic 


per cent 


17.45 


18.39 


17.09 


18.35 




Loss by blasting, per cent 








0.10 




2d evaporation 


0.30 


.039 


0.11 


0.55 




Soluble silica corrected, per cent 


17.75 


18.78 


17.20 


18.30 


18.45 


Alumina and ferric oxide, per 












Cent 


8.46 


9.34 


8.66 


10.21 


q A(] 


Lime per cent 


62.34 


59.73 


53.56 


48.06 


VcTftU 

61.89 


Magnesia per cent 


2.25 


2.07 


1.96 


ffa pp 


1 70 


Sulphuric oxide per cent 


1.41 


1.63 


trace 


LI dCC 

1 70 


JL. i O 

1 O7 


Undetermined, oer cent . 


3.51 


none 


1.98 


J.. I V 

2.70 


Jl.O i 



PHYSICAL TESTS. 

NEAT CEMENTS. 

7 days, Ibs. per square inch .... 770 750 
28 days, Ibs. per square inch.... 826 828 



275 

288 



233 

277 



SOLID BITUMENS. 



CHEMICAL ANALYSES. 

MORTAR, 1 TO 3 BY WEIGHT. 

Theoretical 

Composition 

of Portland 

Cement 

Mortar 

1 to 3 by 

Laboratory Number. 770c. 774c. 771c. 775c. weight. 

Volatile at a red heat, per cent. . 4.93 4.64 4.17 4.80 4.50 
Insoluble in 10 per cent HC1, per 

cent 71/J7 75.38 77.47 78.20 72.70 

Effervescence observed slight slight active active 

Carbon observed 

Soluble silica, 1st evaporation, 

percent 4.21 3.30 4.04 

Loss by blasting, per cent 0.009 0.094 0.091 

2d evaporation, per cent... . 0.01 0.041 0.066 

Soluble silica corrected, per cent 4.21 3.25 2.32 4.02 4.20 
Alumina and ferric oxide, per 

cent 2.24 

Lime, per cent 15.79 

Magnesia, per cent trace 

Sulphuric oxide, per cent trace 

Undetermined, per cent 1.55 

PHYSICAL TESTS. 

MORTAR, 1 TO 3 BY WEIGHT. 

7 days, Ibs. per square inch 231 187 79 64 

28 days. Ibs. per square inch .... 286 235 140 132 

In the examination of concretes from public works a dif- 
ferent basis is used since the New York City specifications 
require that parts shall be taken by measure, while analyses 
are expressed in parts by weight, it was therefore 
necessary to determine the equivalent by measure, in per- 
centage by weight. A number of experiments were made 
upon which to base this estimate. The unit measure of the 
said specifications is a cement barrel and the mortar is to be 
made by adding to it three equal barrels of sand. A barrel of 
Portland cement weighs 380 Ibs. net. Obviously, to get the 
weight of three barrels of sand, the capacity of a cement 
barrel must be known. This, however, is a variable quantity, 
owing to the fact that cements of different brands vary in 
specific gravity, and consequently in bulk for a given weight. 
Thus the capacity of Portland cement barrels range from 3.2 



1.74 


2.39 


2.04 


2.16 


13.83 


12.53 


10.85 


14.12 


trace 


trace 


trace 





trace 


trace 


trace 




1.18 


1.12 


0.10 


2.32 



MISCELLANEOUS METHODS. 257 

cu. ft. to 3.8 cu. ft. The average of the barrels of some twelve 
brands of well-recognized first-class Portland cements shows 
a capacity of 3.34 cu. ft. 

Seven samples of sand from dealers in this city who sup- 
ply contractors, were dried and carefully weighed, showing a 
range from 90 to 101 Ibs. per cu. ft., the average being 97.1 Ibs. 
per cu. ft. 

Broken stone of the size commonly known as i l / 2 ins., 
containing 48 to 50 per cent voids, was found to weigh, when 
dry, approximately 92 Ibs. per cu. ft. 

After a number of concretes had been analyzed air dry, 
it was found that the percentage of water in the air dried con- 
crete must be determined at a constant temperature. It was 
also desirable that the whole sample should be dried at a con- 
stant temperature, in order that the proportions of stone and 
mortar might be comparable. An electrical oven was pro- 
cured in which 2 to 3 kilograms of concrete could be dried 
at a constant temperature of 220 F. The specimens still con- 
tained an average of combined water amounting to 4.5 per 
cent of the mortar, or about 64 Ibs. of water to one barrel of 
cement. 

Therefore the following table shows the composition of a 
good average Portland cement concrete in the proportions of 
1-3-6 to be as follows : 

Broken 

Cement. Sand. Stone. Water. 

Volumes 1. 3. 6. 

Cubic feet 3.33 10.02 20.04 

Pounds 380. 973. 1844. 64. 

Per cent 11.65 29.84 56.55 1.96 

Aside from the fact that these percentages are deduced 
from general averages, and may, therefore, show a variation 
from particular or individual instances, they are also subject 
to a certain modification for the following reason : 

When an analysis of the concrete is attempted, the first 
step after drying the mass at 220 F. is to effect a complete 
mechanical separation of the broken stone and mortar. By 
using a sieve of ten meshes to the linear inch, this separation 
can readily be made, the only source of error lying in the 



258 SOLID BITUMENS. 

amount of gravel that is contained in the sand, and which 
in practice, is never screened. This error would increase the 
percentage of stone and diminish the sand in the mortar by a 
small and uncertain amount. Determined by this method, the 
average percentage of stone and gravel in a concrete of good 
quality should amount to about 60 per cent, as against 56.55 
per cent in the above table. 

This figure will vary with the different cements possibly 
2 per cent with the same kind of stone. As the specific grav- 
ity of cements varies, and as also the specific gravity of the 
sand and stone to a less extent, the relative weights of a unit 
volume, or multiples thereof, will vary to a certain extent. It 
was found, however, that in those cases where the per cent of 
the stone is highest and the cement lowest, that the cement 
is light from excess of unburned cement rock, which is evi- 
dently added intentionally for purposes of adulteration. The 
percentage of stone in the concretes ranges from 77 per cent 
to 52 per cent. These figures exhibit a range of 25 per cent. 
So wide a difference is only to be accounted for on the ground 
of gross carelessness in mixing the concrete. 

In order to establish a standard of comparison for the 
proper proportions by weight between the average first-class 
Portland cement and sand in a cement mortar, as shown by a 
chemical analysis, an estimate was made based on the an- 
alyses made of seven first-class American Portland cements, 
and also a determination of the soluble portion of the sand in 
general use in the preparation of concrete mortars. The per 
cent of mortar found insoluble in 10 per cent HC1 was 4.38 
per cent. The average amount of sand soluble in 10 per cent 
HC1, was found to be 1.07 per cent. From these figures, and 
on the basis that the mortar contains. 

1 vol. dry cement, 3.34 cubic feet 380 pounds. 

3 vols. dry sand, 10.02 cubic feet 973 

Water in combination, 4.5 per cent 64 

Total weight of mortar 1,417 pounds. 

the percentages of matter, soluble and insoluble, in the mortar 
are readily deduced as follows: 



MISCELLANEOUS METHODS. 



259 



Soluble. Insoluble. 

Cement, 380 pounds (95.62%) 363.35 Ibs. (4.38%) 16.65 Ibs. 

Sand, 973 pounds (1.07%) 10.41 Ibs. (98.93%) 962.59 Ibs. 



Total 373.76 Ibs. 979.24 Ibs. 

Per cent of mortar 26.37 per cent. 69.13 per cent. 

The composition of average cement mortar as thus found 
is: 

Insoluble in 10 per cent. HC1 69.13 per cent. 

Soluble in 10 per cent. HC1 26.37 

Volatile at red heat 4.50 

Total 100.00 per cent. 

Of the 26.37 per cent of the mortar that is soluble in 10 
per cent HC1 there are certain constituents which go to form 
the active principle or cementing power of the mortar or con- 
crete. These, of course, are principally contained in the ce- 
ment and consist of soluble silica, alumina and iron oxide and 
lime. 

The proportions of these ingredients in terms of percent- 
ages of the mortar were determined as follows, by using data 
obtained from previous work in this line, thus : 

An average of the analyses of the seven first-class Port- 
land cements previously referred to showed the proportions 
of the above mentioned ingredients to be, in terms of percent- 
ages of the cement : 

Soluble silica 18.45 per cent. 

Alumina and ferric oxide 9.46 " 

Lime 61.89 

Analysis of the sand for the same purpose gave in terms 
of percentages of the sand : 

Soluble silica 0.25 per cent. 

Alumina and ferric oxide 0.23 " 

Lime 06 

In both the cement and the sand there are, of course, 
other ingredients either insoluble or inactive which need not 
be considered in this connection. 

Then if we consider, as before, that a Portland cement 
mortar, (i to 3 by volume) will contain 380 Ibs. of cement, 973 
Ibs. of sand and 64 Ibs. of water in combination, the quanti- 
ties of the soluble silica, alumina and ferric oxide and lime in 
the mortar will be as follows : 



26o 

Al. and Fe. 

Soluble Silica. Lbs. Oxides. Lbs. Lime. Lbs. 

Cement (8.45% of 380) 70.11 (9.46% of 380) 35.95 (61.89% of 380) 235.18 

Sand .(10.25% 973) 2.43 (0.23% of 973) 2.24 ( .06% of 973) 0.58 

Total 72.54 38.19 235.76 

Which in percentages of mortar amount to: 

Soluble silica 5.12 per cent. 

Alumina and ferric oxide 2.70 " 

Lime 16.64 

Making a total of 24.46 per cent. 

which subtracted from 26.37 P er cent (the entire amount solu- 
ble in 10 per cent HC1 as shown in the schedule on page 259), 
leaves 1.91 per cent of the soluble matter which is inactive, 
consisting of magnesia, sulphuric oxide, alkalies, etc. 

A summary of the results obtained from the preceding 
calculations then shows that a good average Portland cement 
concrete, in the proportions of 1-3-6 by volume, should give 
in percentages by weight approximately : 

f Broken stone. 5.554 to 604 

Insoluble, 69.15$ 
Concrete J Mortar consisting of 



cement, sand and 
water in combination 
I 404 to 43. 45 4 



Volatile at red heat, 4.50 * 



I 



Inactive, 1.91 



Soluble, 26.37*X (Soluble silica . 5.12* 

LActive, 24.46$ J Alumina an d 

j feme oxide. 2.704 
I Lime 16. (.4 * 

In order to ascertain to what extent these figures, shown 
on page 259, are confirmed by the practical work of the lab- 
oratory, briquettes were made of a first-class Portland ce- 
ment, with standard crushed quartz, proportions I to 3 by vol- 
ume, and also w r ith a quartz sand in very general use in con- 
crete constructions about the city of New York. The cement 
was first analyzed when the briquettes were analyzed, the first 
contained 68.19 per cent insoluble in 10 per cent HC1, the sec- 
ond 68.07 P er cent, and the third 69.55 P er cent. A fourth 
briquette was made from mortar taken from a mortar board 
where cement concrete was being mixed by hand. This mortar, 
when air-dried, contained 71.3 per cent of matter insoluble in 10 
per cent HC1. Another briquette, from a mortar made 
from another cement contained 72.14 per cent insoluble in 10 



MISCELLANEOUS METHODS. 261 

per cent HC1. The average insoluble matter in these five 
mortars was 69.85 per cent. It is probable that with different 
sands and cements, and for practical purposes, an average of 
70 per cent would not be far from correct. The average 
amount of active cement found in these five cement mortars 
by Newberry's formula is 23.17 per cent. As an empirical 
formula, it has been found to indicate in instances, now 
amounting to hundreds, the value of a cement for practical 
purposes, in a most satisfactory manner. 

In order to determine the percentages by weight of solu- 
ble silica, alumina and iron oxide taken together, and lime, 
the sum of which percentages indicates the entire amount of 
active cement in any cement mortar or concrete, according to 
Newberry's formula, it was assumed that no injustice would 
be done in any comparison that might be made if the soluble 
silica was used as a unit of comparison after the following 
manner: The sand used was a clean quartz containing about 
I per cent of iron oxide and other matter, which was soluble 
in 10 per cent HC1. The amount so soluble was sufficient to 
increase the percentages of alumina and iron oxide present, 
but the amount of sand used in the mortar being very vari- 
able, the amount of iron accruing from this cause was incon- 
stant. It was therefore determined to assume on the basis 
of the average results that the amount of alumina and iron 
oxide legitimately constituting the active cement present 
shall be computed at one-half the soluble silica present. Then, 
using Newberry's formula, and multiplying the percentage of 
soluble silica by 2.8, and one-half of that percentage by i.i, 
and adding the products together, the sum thus found repre- 
sents the percentage of lime that, in combination with soluble 
silica, alumina and iron oxide, formed the active cement pres- 
ent. The soluble silica found by analysis, plus one-half such 
amount computed as alumina and iron oxide, plus the lime 
computed as above indicated, equals the percentage of active 
cement found in any concrete.* 



*Rerort of the Commissioners of Accounts of the City of New York, July 
27, 1905. 



PART III. 

THE PHYSICAL PROPERTIES OF 
SOLID BITUMENS. 



CHAPTER XV. 
SPECIFIC GRAVITY, ETC. 

The specific gravity of solid bitumens may be taken by 
any known method. As natural bitumens are seldom pure, 
and the^ mixtures vary even in the same kind of bitumen, 
from the same deposit, any comparisons based on specific 
gravity give little satisfaction and are of little value. 

There are experimenters who claim to have obtained sat- 
isfactory results when operating upon bitumens that have 
been obtained by the evaporation of solutions of natural bitu- 
mens obtained by various solvents, thus excluding the impuri- 
ties. These results vary very little from 1,000. Some of these 
extracts sink while others float. The differences are so small 
as to signify very little. The Westphal balance is a conve- 
nient instrument, where extreme accuracy is not desired ; but 
close work must be done with the bottle or the balance alone. 
In the experience of the author, but little is learned to com- 
pensate for the time required in the determination of the 
specific gravities of solid bitumens. 

SOFTENING POINT. 

As a means of comparison the determination of the soft- 
ening point is of some value. It consists in the empirical de- 
termination of the temperature at which a given specimen of 
bitumen will melt or lose form. A variety of methods have 
been contrived for making this determination, which, taken 
together as a group, passes into another group that is de- 
signed to ascertain the temperature at which a given speci- 
men will flow. The dividing line between the two groups is 
arbitrary and not very distinct. I shall describe the appara- 
tus as referred to one class or the other by their inventors. 

MABERY AND SIEPLEIN. 

C. F. Mabery and O. J. Sieplein investigated the soften- 
ing and melting points of solid bitumens and suggested the 

262 



SPECIFIC GK.inry, ETC. 



263 



following described apparatus (Fig. 16). "In a glycerine-bath in 
a beaker of moderate size is placed a narrow beaker closed with 
a cork through which is passed a thermometer. There is also 
inserted through the cork close to the side of the narrow 
beaker, a strip of metal, y 2 in. wide, bent over the side of the 
beaker as a support, and extending to within y 2 in. of the 
bottom of the beaker. The lower end of the metal strip is 
bent at a right angle and the narrow corners are bent upwards. 
The bend in the metal is used as a support for the section of 
asphalt which is pressed on the points, formed by the corners 
of the metal. The dimensions of the apparatus used by us 




Fig. 16. Mabery and Sieplein's Apparatus. 

are given, but evidently the only constants need be the dis- 
tance of the thermometer from the specimen; the distance of 
the metal from the bottom of the beaker, the width of the 
metal strip and the dimensions of the specimens to be tested. 
With the metal strip V 2 in. wide the specimen to be tested 
is cut or molded of sufficient length to project % in. on either 
side of the metal. 'The observation consists in noting the 
temperature at which the specimen softens and becomes suf- 
ficiently fluid to fall on either side of the metal support and 
just touch the bottom of the beaker. We found it convenient 
to place a disk of copper on the bottom of the inside beaker, 
since it could be removed after the observation, and the as- 



264 SOLID BITUMENS. 

phalt that, had fallen more conveniently cleaned than from 
the bottom of the beaker. While a Bunsen flame is the more 
convenient source of heat, an alcohol or oil lamp can be used. 
Evidently the time of heating should not vary widely, al- 
though we have found a variation of five minutes had no ap- 
preciable effect on the melting points. 

"The dimensions of the different parts of the apparatus 
are: 

Inches. 

Width of outside beaker 2% 

Height of outside beaker 3% 

Width of inside beaker '. 1% 

Height of inside beai:er 4% 

Width of metal support % 

Length of lower bend of support % 

Distance of specimen from false bottom of beaker. . % 

Standard size of specimen 1 x l /2 x % 

"In testing the efficiency of this method, observations 
were made of the initial temperature, of the temperature at 
the time when the softened material just touched the bottom 
of the beaker, and the time (duration) of heating."* 

For high melting points, an air-bath or a paraffine-bath is 
used. 

J. KOVACS. 

"For the determination of hard and soft grade asphalts 
the apparatus is described as follows: 

"On a sand-bath S (Fig. 17), 160 mm. (6 in.) diameter, 
with a lo-mm. (3/8 in.) layer of sand, a beaker, O, is placed, 
of about no mm. diameter (41/3 in.) diameter and 160 mm. 
(6 in.) high, containing sufficient rape-seed oil or gylcerine 
to cover the beaker L, 90 mm. (3^/2 in.) diameter and 160 mm. 
(6 in.) high three-quarters of its height. In this air-bath 
the dropping frame is placed, Fig. 18, top view; Fig. 19, side 
view. It consists of a strong brass disc, 3 mm. (y& in.) 
thick and 83 mm. (3*4 in.) diameter, perforated in the 
center for a thermometer and with four perforations of 2 mm. 
(3/32 in.) diameter, around each of which a brass cylinder of 
12 mm. (1/2 in.) inner diameter and 15 mm. (5/8 in.) high is 



*Jour. Am. Chem. Soc., xxiii, p. 16; Jour. Soc. Chem. Ind.. xx, p. .394; Koh- 
ler, p. 352. 



SPECIFIC GRAVITY. ETC. 



soldered. The disc is supported on three feet, each 60 mm. 
(2% in.) high. A regulated Bunsen burner is placed under 
the sand-bath, so that the temperature of the air-bath is evenly 
raised in each determination. The air-bath is supported from 
the ring of a retort stand, and the annular space between it 
and the sides of the oil-bath is covered by a large, flat, per- 
forated cork. The tubes of the dropping frame should be 
numbered 1-4. 





Fig. 18. 




Fig. 19. 



Fig. 17. 



J. Kova.cs' Apparatus. 



"In testing hard asphalt, a portion is formed into a pellet, 
weighed, and allowed to stand from 10 to 20 minutes. A pel- 
let is then inserted in each of the numbered tubes of the drop- 
ping frame, which is immediately placed in the air-bath with a 
thermometer; a thermometer is also suspended in the oil-bath, 
and a gas burner is placed under the sand-bath. After some 
time the softened bitumen is visible underneath the perforated 
disc, and the instant it drops, the temperature of the air-bath 
is noted. Bitumens for foot pavements should not drop inside 
80 C., and for roadways, not under 105 C. 



266 SOLID BITUMENS. 

"It is impossible to give a process for precisely determin- 
ing the adulteration of a natural bitumen with petroleum 
pitch up to 20-25 per cent., but its presence can be proved 
quite well by the chemical tests described on pages 198-202."* 
The following are some results that were obtained with 
this apparatus : 

Dripping 
Kind of Asphalt. Temperature. 

No. 1. Dalmatian asphalt 97.0 C. 

No. 2. Trinidad asphalt 93.5 C. 

No. 3. Tartaros asphalt 114.0 C. 

No. 4. Normal 105.0 C. 

Kind of Pitch. Softening Point. Melting Point. 

Soft. 40 C. 50 C. 

Medium. 60 C. 70 C. 

Hard. 80 C. 90 to 110 C. 

According to Lunge (Lunge-Kohler, Ind. d. Stein Kohlen- 

teers u. Ammoniaks 4 Ed. i, p. 431), chewing is a practical 

test. If it chews easily it is soft, if with more difficulty, it is 

medium ; if it becomes pulverized in chewing, it is hard. The 

soft pitch is glistening and blacker than the hardest, which 

contains more matter which is of a grayish tint.t 

HOLMES. 

J. G. Holmes remarks as follows concerning researches 
upon pitch. Several pieces of pitch from different parts of the 
sample are cut into cubes of about 13 mm., then they are 
stuck upon wires which are heated and the pitch fastened 
upon them. The pieces are then sunk in a vessel holding 500 
cc. of water and the temperature simultaneously raised at the 
rate of about 5 a minute. The thermometer should be in- 
serted in the vessel in such manner that it should be 4 or 5 
cm. from the bottom, and the cubes should be immersed even 
with the thermometer bulb. As soon as the temperature rises 
the cubes are taken out from time to time and squeezed 
together with the fingers. The temperature is noticed at 
which the following appearances are shown : 

1. Softening. 

2. Strong softening. 

3. Melting. 

Chem. Rev. d. Fett u. Harz Ind. 1902, p. 156. Jour. Soc. Chem. Ind. 
xxi, p. 1077, 1902. 

tKohler, Chem. u. Tech. d. Nat. u. Kunst. Asphalte, p. 353. 



SPECIFIC GRAvrrr, ETC. 2 6? 

Softening is indicated when the pitch can be drawn out 
spirally with ease ; strong softening when it yields easily to 
the fingers ; and melting when the pitch drops off the wires.* 

THE FRENCH METHOD WITH CYLINDERS. 

Accurate results are obtained in the following way, which 
is used in the French industry. The tin cylinder (Fig. 20), 
contains a horizontal partition into which are soldered five 
tubes, closed at the bottom. The middle tube serves for the 
introduction of a thermometer, the four others for the recep- 
tion of ground and sifted pitch. The large pieces and the 
dust should be removed by means of a sieve. The pitch 
powder is loaded with an iron piston and rod of a determined 
weight, which rods, as well as the thermometer, pass through 
holes in the cover of the cylinder, which serve as guides. 
The cylinder is filled with water, or, for pitches of high melt- 
ing point, with solution of common salt, to a point above the 
top of the tubes, and heated with a lamp until the pistons 
sink in the melted pitch, which temperature should be noted 
as the melting point. 

A massive steel cylinder is better than this tin vessel in 
which are bored five openings for the tubes and the thermom- 
eter.f 

MUCK. 

Pitch Stick Method. According to Muck, the determina- 
tion of the softening temperature is accomplished in the fol- 
lowing manner: From the sample of pitch to be examined, 
small cylindrical sticks of 4 mm. diameter and 100 mm. length 
are molded ; about 20 mm. of the stick is bent around the 
bulb of a thermometer and held by a rubber band in such a 
manner that the stick stands parallel with the thermometer 
tube. Thus mounted the stick and tube are placed in a Becker 
glass filled with water, to which is attached a vertical stirrer, 
and heated until the long leg of the stick of pitch begins to 
bend over. This method is as much to be depended on as are 
the others of similar purpose already proposed.! 

*Lunge-K6hler, Ind. d. Stein Kohlenteers u. Ammoniaks 4, Ed. 1, p. 
432. Kohler, p. 354. 

tKohler, Chem. u. Tech. s. 355. 

$Zeitchr. f. Berge, Hutten-u. Salinenwesen. 188S, vol. 37; KShler, s. 355. 



268 



SOLID BlTl'MI-:\'S. 



BUCHANAN. 

Another Pitch Stick Method. Buchanan sticks a suitable 
pitch stick to a thermometer tube placed in a dry test tube 
and heated in a water-bath. The pitch first softens and then 
falls off, which indicates the melting point. In this way he 
found the melting point of hard pitch to be at 80, of medium 
at 55, and of soft pitch at 50.* 

SCHENK ZU SCHWEINSBERG. 

Method with Bent Tubes. E. Schenk zu Schweinsberg 
uses the following method for determining the melting point 
of pitch and the condition of fluidity or flowing. A glass tube 





Fig. 20. 
French method with cylinders. 



Fig. 21. 
Schenk zu Schweinsberg's method. 



(Fig. 21 ) about / mm. wide and 25 mm. long, is bent and 
drawn out over a gas flame into the form shown in Fig. 21. 
The lower part is then filled to the line ef w r ith pitch finely 
crushed in a mortar ; in case the pitch is too soft for the mor- 
tar, small balls are formed and the lower bent part of the glass 
tube filled with them. Upon the surface of the pitch is placed 
a drop of mercury. The tube is next drawn out at its narrow 
part in the flame to a pointed capillary tube. A platinum 
wire is then fitted to the tube abcdq, by which a small sling 
is formed for the support of the point of the glass tube, 

*Jour. Soc. Chem. Ind., 1894, p. 1098. Kohler, p. 356. 



SPECIFIC GRAl'ITY, ETC. 269 

while the wire at bq and cd makes a ring around the tube in 
which it is slung; at d a small loop is made in this wire into 
which is inserted a small glass rod which serves as a support 
for the apparatus in a Becker glass of water. Beside the small 
tube a thermometer is suspended, the bulb of which shall be 
at the same level as the specimen of pitch. The water is very 
slowly warmed and any gas bubbles that adhere to the sur- 
face of the apparatus may be removed by the tip of a feather. 
The pitch settles together with the rise of temperature, so 
that finally the mass of the pitch is only one-half the original 
volume. As the melting point of the pitch is reached it has 
the appearance of expanding. The approach of the melting 
can be most easily observed at the bent portion and the point 
of the apparatus. As soon as the expansion commences, the 
thermometer is read, which now gives the melting point of 
the pitch. The warming is continued slowly until the pitch 
in the tube rises, when the drop of mercury sinks and is en- 
closed by the fluid mass. This fluidity of the pitch, whereby 
the whole lower part of the tube is filled with fluid pitch and 
mercury, Schenck zu Schweinsberg calls the practical melting 
point and reads the temperature corresponding to these phe- 
nomena. He demonstrates as soft pitch all whose melting 
point is under 60, as medium hard all whose melting point 
is from 60 to 99, and as hard those whose melting point lies 
above 100.* 

KLIMONT. 

Test-Tube and Cone Methods. J. Klimont declares the 
method of Schenk zu Schweinsberg to be the most reliable for 
the determination of the softening and melting temperatures 
of coal-tar pitch, but it should be pointed out that only in the 
hands of an analyst who has made them frequently, will it give 
results to be depended upon, as the expansion as well as the 
sinking of the drop of mercury in the fine pitch dust, which 
at the same time covers the surface of the same, is very diffi- 
cult of recognition by an untrained eye in no way accustomed 
to observe. Klimont fixes both as the important points in 
technical research by means of the following simple tests: 



*Osterr. Zeitschr. f. Berr;-u. Hutten wesen, 1890, p. 463; Zeitschr. f. angew. 
Chemie., 1890. p. 704; Ktthler, p. 356. 



270 SOLID BITUMENS. 

(i) An ordinary test-tube is filled with the finely pul- 
verized pitch by pouring it through a funnel with a long neck, 
the bottom of the tube is jarred gently upon the table until 
the powder is collected into a compact mass which a little 
more than fills the curved part of the test-tube. Then 
if the pitch is soft or medium hard, the test-tube is suspended 
by a wire in a Becker glass of water with a thermometer the 
bulb of which shall be at the same level as the pitch. For 
hard pitch the determination is made in a glycerin-bath. It is 
slowly warmed over a Bunsen burner, the flame of which is 
2 cm. in height ; as soon as the edge of the pitch dust or the 
little balls melt together and the mat of pitch dust will bright- 
en the sides of the vessel, the melting process begins and the 
temperature is read. As soon as the pitch on the sides melts, 
then, finally, the whole surface will become smooth and glis- 
ten. As soon as this moment is observed, which indicates 
the end of the melting process and also Schenk zu Schweins- 
berg's point of fluidity, the temperature is noted. 

Still more noticeable are the temperatures by the follow- 
ing tests : 

(2). The pitch under examination is quickly softened in 
a flame until it will knead ; it is then rolled and drawn into a 
cone about 3 mm. base and 5 mm. high. The point is now 
seized with the pincers, the base softened in a flame and the 
cone stuck to the bottom of a small tube 7 mm. in diameter by 
35 mm. high, so that the whole cone stands perpendicularly. 
The tube is reversed until the cone is cold. Mercury is then 
poured into the tube until the point of the cone is no longer in 
sight and the tube is warmed in a Becker glass of either water 
or glycerine, as before described. 

At the surface of the mercury a black point suddenly ap- 
pears. The temperature at which this phenomenon occurs is 
the beginning of the melt and corresponds with the melting 
point of Schenk zu Schweinsberg. By warming longer the 
pitch drop spreads out upon the mercury and this temperature 
approaches the point of fluidity of Schenk zu Schweinsberg. 

By a comparison of the method of Schenk zu Schweins- 
berg with that of Klimont, medium hard pitch gave the follow- 
ing degrees of temperature :* 

*Zeitschr. f. angew. chem., 1900, p. 761; Kohler, p. 357. 



SPECIFIC GRAVITY, ETC. 271 

Schenk zu Schweinsberg. Klimont (1). Klimont (2). 

Melting Point of Melting Point of Melting Point of 

Point. Fluidity. Point. Fluidity. Point. Fluidity. 

Degs. Degs. Degs. Degs. Degs. Degs. 

No. 1 62 66 64 67 64 67 

No. 2 60 65 60 65 60 63 

No. 3 80 85 79 80 79 84 

No. 4 52 57 52 57 52 57 

No. 5 60 65 60 66 60 63" 

KRAMER AND SARNOW. 

Straight Tube Method. According to G. Kramer and 
E. Sarnow most of these methods for the determination of the 
melting and softening points of asphalts and asphaltic bodies 
are uncertain, because they are so dependent upon the per- 
sonal equation that differences of 5 to 10 are not of rare 
occurrence. The use of Engler's Viscosimeter, which is 
prescribed in the official catalogue for petroleum residuums, 
in which the accuracy is mostly interfered with by the con- 
siderable adhesion of the substance to the walls of the open- 
ing through which it flows, is open to some criticism. The 
methods are better which rest upon the observed time at 
which a heavy body sinks in the material, which by being 
warmed approaches the melting point.* 

"Aktien Gesellschaft fur Teer-und Erdolindustrie" Meth- 
od. Reliable results are obtained by the use of processes 
worked out and named, which in the industry of the Aktien 
gesellschaft fiir Teer-und Erdolindustrie, have been generally 
introduced and for a long time and by a very great number 
of determinations, have been recommended. About 25 gms. 
of the pitch or asphalt under investigation are melted in a 
small tin vessel with an even bottom (Fig. 22) in an oil- 
bath of a form as shown at about 150, the height of the mol- 
ten pitch being about 10 mm. In this a glass tube open at 
both ends and some 10 cm. in length, is dipped in such a man- 
ner that 6 or 7 mm. of the tube are filled with the melted 
pitch; the other end of the tube is closed with the finger 
and the pitch in the full end is allowed to cool by revolving 
it horizontally in the air. As soon as the pitch will no longer 
flow, the pitch on the outside of the tube is removed. The 

*Cheni. Ind. 1903, p. 55; K8hler, 358. 



272 



SOLID BITUMENS. 



height of the pitch in the tube should be, as a rule, about 5 
mm. Upon this is placed 5 gms. of mercury which for this 
purpose may be measured in a marked tube. The tube is sus- 
pended in a Becker Glass full of water, which again is sus- 
pended in a second glass of water (Fig. 23). In the inner glass 
of water is placed a thermometer in such a position that the 
bulb thereof is at the same level as the layer of pitch in the 
tube. The water is now heated with a moderate flame. The 
temperature at which the mercury breaks through is noted as 
the softening and melting point of the pitch or asphalt. 






Fig. 22. Fig. 23. 

"Aktien Gesellschaft fur Teer-und Erdolindustrie" method. 

It can be readily seen that the apparatus as shown in Fig. 
23, not only permits one but several tubes holding pitch or 
asphalt to be observed at the same time, so that the melting 
points of several samples can be taken simultaneously. For 
asphalt the melting point of which is higher than 90, the 
outer Becker glass should be filled with paraffine oil, and the 
inner with a saturated solution of common salt or magnesium 
chloride. 



SPECIFIC GRAVITY, ETC. 273 

The melting points found by methods heretofore em- 
ployed differ by a few degrees ; that is, they are so much 
lower. They are somewhat influenced by the diameter of 
the tube, the thickness of the layer of pitch and the height of 
the column of mercury. With like quantities of mercury (5 
gms.), the increased diameter is compensated by the decreased 
height of the layer of mercury. As has been pointed out, the 
influence of the thickness of the layer of pitch within certain 
limits, is not noticeable. A layer of pitch of 5, 6 and 7 mm. 
in thickness gave 61.5, 60.5 and 61.5 as the softening points. 

As illustrating the reliability of the process, the following 
single determination of different localities is given : 

Soft Pitch. Medium Hard. Hard Pitch. 
Origin. Degrees C. Degrees C. Degrees C. 

Grabow, Moravia 51.0 68.5 80.0 

Grabow, Moravia 51.5 68.5 80.0 

Grabow, Moravia 51.5 68.2 80.8 

Grabow, Moravia 51.3 69.0 80.5 

Niederau, Saxony .... .... 83.0 

Niederait, Saxony 84.0 

Pasing, Bavaria 83.5 

Pasing, Bavaria .... .... 84.5 

Erkner ' 50.0 61.5 87.0 

Erkner 50.5 60.5 86.0 

Erkner 51.0 61.5 87.0 

A mastic block that gave in Grabow a softening point of 
58, likewise gave in Berlin 58. Other different asphalts and 
asphaltic bodies were examined by the same process and also 
with the usual capillary method and gave the following re- 
sults:* 

After 

Kramer and Sarnow. By Capillarity. 

Degrees C Degrees C. 

Cerisin 52.0 '4-7.0 to 53.0 

Beeswax 55.5 61.5 to 63.5 

Paraffin 46.0 45.0 to 48.0 

Asphalt, refined, hard 51.5 to 52.0 Wholly indistinct 

Asphalt B, glass, hard : 82.0 Wholly indistinct 

Petroleum residuum, Alsace petroleum. 105.0 

Colophony , 67.0 to 67.5 

*K5hler, Chem. u. Tech. d. Nat. u. Kunst. Asphalte, p. 359. 



274 SOLID BITUMENS. 

FLOW. 

This test as applied to different samples of solid bitumens 
is wholly empirical, arbitrary and relative. It consists in pre- 
paring cubes of about half an inch dimensions, of the material 
to be tested and also cubes of the same dimensions of any sim- 
ilar material that may be selected as a standard of compari- 
son. A cube of each variety is placed in a warming oven 
supplied with a glass door, upon a glass plate inclined at a 
slight angle. A uniform source of heat is applied and the tem- 
perature and time noted at which the two cubes lose form 
and then flow down the plate. The length of the flow upon 
the plate is also noted. 

The significance and value of the results obtained from 
this test depend wholly upon the selection of the standard 
specimen to be used for the comparison. 

DUCTILITY. 

This term has been used to designate those properties by 
virtue of which a metal can be drawn into wire. By analogy 
the term is applied to solid bitumens and designates the sim- 
ilar properties possessed by them in varying degree by which 
they may be extended without fracture. A bitumen that can 
be extended into long threads is said to be ductile. One that 
cannot be extended but breaks abruptly is said to be short. 

Mr. A. W. Dow has contrived an apparatus by which he 
measures this property, which he describes as follows: 

"The ductility of an asphaltic cement is determined by 
ascertaining the distance in centimeters that a prism of the 
cement can be drawn out before breaking. The size of the 
prism that I have adopted is one 5 cm. in length and with a 
square cross section of i cm. The molding of this prism is 
done as follows : Fig. 24 shows the four pieces which fit to- 
gether to make the mold. Fig. 25 shows the mold put together 
for filling. Before fitting, the mold is put together on a brass- 
plate, and to prevent the asphalt adhering this plate and the 
inner sides of the two pieces of the mold (a and a) are amal- 
gamated. The asphalt cement to be tested is poured into the 
mold while in a molten state, a slight excess being added to 
allow for the shrinkage on cooling. After the asphalt cement 
is nearly cooled the prism section is smoothed off level by 



SPECIFIC GRAVITY, ETC. 



275 



means of a trowel, which should be wet with water to prevent 
its sticking. When it is thoroughly cooled to the temperature 
at which it is desired to make the test, the clamp and two side 
pieces are removed, leaving the prism of asphalt cement held 
at each end by the ends of the mold that now take the part 
of clips. The test is made by pulling the two clips apart at a 
uniform rate of speed by means of hooks inserted in the eyes. 
The prism should be kept in the freezing mixture or water at 
the temperature desired, and the test made while so immersed 
so as to insure the temperature remaining constant. The rate 




a 




Fig. 24. Fig. 25. 

Dow's Ductility Apparatus. 

of speed adopted for pulling the clips apart where the test is 
made at 77 F. is 5 cm. a minute, and I cm. per minute where 
making .the test at 20 F. Up to the present time I have 
pulled tjqe clips apart -by hand, but am now working on a 
machine; that. will do this and at the same time measure the 
force required to pull the clips apart at the standard rate of 

speed." ,* 

PENETRATION. 

A. W. Dow. 

"Tfre' softness of : an asphaltic cement is determined by 
ascertaining its consistency or penetration by means of the 



2 7 6 



SOLID BITUMENS. 



penetrating machine, at 32, 77, 100 and 115 F. The rate 
of softening of an asphaltic cement is thus determined, and 
an idea can be arrived at as to whether it would be too soft 
for use at the maximum climatic temperature. 

"The consistency or viscosity of an asphaltic cement is 
determined by ascertaining the distance that a standard needle 
will penetrate into it under a standard weight and in a stan- 
dard interval of time. The distance that the needle penetrates 
is called the penetration of the sample. There are three types 
of apparatus all depending on the same principle, that of a 
needle penetrating, that have been described. The first ap- 




Fig. 26. Penetration Needle 

paratus was devised by Prof. H. C. Bowen in 1888 and is 
patented (Patent No. 494974). It is also described by Mr. 
Richardson in his report to the Engineer Commis- 
sioner of the District of Columbia for the year end- 
ing June 30, 1891, p. 1 06. The author describes 
still another sort of apparatus in the report of the Operations 
of the Engineer Department of the District of Columbia for 
the year ending June 30, 1898. This apparatus has been found 
very economical for experimental work, but being rather cum- 
bersome to have in paving yards, etc., a simpler apparatus 
was devised which answers all purposes, even experimental 
work. The latter is shown in the accompanying figures, Nos. 
27 and 28. 

In Fig. 26 is shown the No. 2 needle, A, inserted in a 
short brass rod, which is held in an aluminum rod (C) by the 



SPECIFIC GRAVITY, ETC. 



277 



binding screw, B. The aluminum is secured in a frame work 
so weighed and balanced that where it is supported on the 
point of the needle A, the framework and rod will stand in an 
upright position, allowing the needle to penetrate perpendicu- 
larly without the aid of a support. The frame, aluminum rod 
and needle weigh 50 grams ; additional weight, when desired, 





Fig. 2\ 



Fig. 28. 



Dow's Penetrating Apparatus. 



is placed on the bottom of the frame at W. In Figs. 27 and 28 
are shown the side and front views of the entire apparatus put 
together and ready for making a penetration. D is a shelf for 
the sample. E is a clamp to hold the aluminum rod C until 
it is desired to make the test. F is a button which when 
pressed opens clamp E. By turning this button while the 



278 SOLID BITUMEXS. 

clamp is being held open, it will lock and keep the clamp from 
closing until unlocked. The device to measure the distance 
penetrated by the needle consists of a rack, the foot of which 
is G. The movement of this rack up or down turns a pinion 
to which is attached the hand which indicates on the dial K 
the distance moved by the rack. One division of the dial 
corresponds to a movement of the rack of i/ioo cm. H is a 
weight hung by a coarse thread which winds on a drum on 
the axle of the spindle and counterbalances the rack so that 
the rack can be raised or lowered by moving this counter- 
weight H up and down. L is the tin box containing the sam- 
ple to be tested, which is covered with water in a 
crystallizing dish, thus keeping its temperateure constant, 
MM are leveling screws. Fig. 29 represents a clock move- 
ment having a lo-inch pendulum attached to the wall to one 





Fig. 29. Pendulum. 

side of the machine, used for timing the test. Make a mark, 
P, on the wall just at the extremity of the swing of the pendu- 
lum. A double swing of this pendulum that is, from the 
time it leaves P until it returns is one second; 

"To make the penetration test, the samples of asphalt 
cement contained in circular tins, along with the glass, dish, 
are placed in a receptacle containing at least 5 ins. of water, 
which should have been previously brought to the tempera- 
ture at which it is desirous to make the rest. While the sam- 
ples are under the water it should be stirred every- few min- 
utes, best with a thermometer, and the temperature kept con- 
stant when necessary by the addition of hot or cold water as 
the case may require. The samples should remain under the 
water at least fifteen minutes, and in cases when their temper- 
ature is not near that at which the test is to be made they 



SPECIFIC GRAVITY, ETC. 



279 



should be left in possibly half an hour. After the samples 
have remained in the water a sufficient time to have attained 
their temperature they are ready to be penetrated. 

"One of the samples is now placed in a glass dish and 
removed in it, covered with as much water at the standard 
temperature as is convenient without spilling. The glass cup 
containing the sample is placed on shelf, D, under C, as shown 
in Figs. 27 and 28. Insert brass rod with needle into C, and 
secure by tightening binding screw B. Lower C until the 
point of needle very nearly touches surface, then, by grasping 
the frame with two hands at S and S', Fig. 28, cautiously pull 
down until needle is just in contact with surface of sample. 
This can be best seen by having a light so situated that look- 
ing through the sides of the glass cup the needle will be seen 
reflected in the surface of the sample. After thus setting the 
needle, raise counterweight slowly until the foot of rack G 
rests on the head of rod C ; note reading of the dial. Place 
thumb of right hand on R and press button, F, with fore- 
finger, thus opening clamp. Hold open for the desired time 
and then allow it to close. Raise counterweight H as before 
until foot of sack rests on rod C. The difference between the 
former reading of the dial arid the present is the distance 
penetrated by the needle or the penetration of the sample. 
Raise rack, loosen binding screw B, raise rod, through clamp, 
having the needle sticking in sample. Remove needle from 
sample, clean well by passing through a dry cloth, replace 
needle in C, and the machine is ready for another test." 

"The needle which I have adopted as a standard for pene- 
trating is a No. 2, manufactured by R. J. Roberts, Redditch, 
England. All the needles, however, obtained in a package, 
cannot be used for penetrating, as they vary somewhat in 
shape, and only those are selected which give a penetration 
corresponding to a standard needle. The standards that I 
have adopted for this mchine are t 32 F. or lower, the dis- 
tanc in hundredths of a centimeter that a No. 2 needle will 
penetrate into the sample in one minute of time when weight- 
ed with 200 gms. ; for tests made at a temperature of 77 F., 
the distance in hundredths of a centimeter that a No. 2 needle 
will penetrate into the sample in five seconds of time when 
weighted with 100 gms. For tests made at a temperature of 



280 SOLID BITUMENS. 

100 F., or above, the distance in hundredths of a centimeter 
that a No. 2 needle will penetrate in five seconds of time 
weighted with 50 gms.''* 

I have given a description of this apparatus in Mr. Dow's 
own words. 

This apparatus is of great value, especially in this im- 
proved form. It is chiefly valuable for comparison of different 
samples of the same kind of bitumen, under the same condi- 
tions. It will not indicate chemical stability and should be 
strictly confined to those physical properties that it indicates 
within its own limitations. 

*Proc. Am. Soc. for Testing Materials, 1903, Vol. Ill, pp. 352-357. 



PART IV. 

CHEMICAL TECHNOLOGY OF 
BITUMINOUS STREETS. 



CHAPTER XVI. 
HISTORICAL INTRODUCTION. 

Although asphaltum and other forms of solid bitumen 
have been used since the dawn of history, their general use as 
articles of commerce is almost wholly confined to the eigh- 
teenth and nineteenth centuries. Cisterns and silos that are 
lined with solid bitumen, said to be still intact, are found in 
Petrea and Egypt, and they must be from two to three thou- 
sand years old; yet, the manner of their construction, the 
locality from which the bitumen was obtained, and by whom 
they w r ere built, can only be conjectured.* 

In 1721, Eirinis d' Erynys, a Greek physician, published a 
pamphlet in Paris, France, in which he described the deposits 
of bituminous sandstone and limestone found at Val de Trav- 
ers, canton of Neufchatel, Switzerland, in the upper valley of 
the Rhone. He compares these deposits of bituminous rock 
with similar beds that occur in the valley of Siddim near 
Babylon. These deposits were forgotten for nearly a cen- 
tury and then rediscovered. 

I have sought in vain for any record of the person who 
first suggested the use of this material for paving. The idea 
was no doubt original in more than one locality, as I have dis- 
covered traditional evidence that in the valley of the Rhone, 
in Trinidad and in California, it was observed that the frag- 
ments of asphalt that were jolted from carts, were crushed 
and compacted into a solid rock bed, by the wheels of the 
carts that followed. The conviction that other road beds 
could be constructed of the same material was inevitable. 

In 1797, the French government made a concession to 
M. Secretan of all country between Seyssel and Belgarde on 
both sides of the Rhone, fourteen miles in length by one and 
one-half miles in width. This concession was in litigation 
fifty years. 

In 1834, Puvis described the methods employed at the 

*Paving and Munic. Engineering, x. p. 381. 

28l 



282 SOLID BITUMENS. 

Seyssel works, for extracting the bitumen. He describes the 
sandstone as containing from 2 to 3 per cent and the lime- 
stone as much as 9 per cent, of bitumen.* 

In 1850, M. De Coulaine published a very important paper, 
in which he discussed bituminous rock streets in a manner 
that in the light of our present knowledge and experience 
appears very remarkable. f 

"The Annals of Bridges and Roads" is a publication is- 
sued by the French government, containing reports by the 
different engineers having in charge the public roads of 
France, together with memoirs upon subjects pertaining to 
the construction and maintenance of bridges and roadways. 
It is a work of the greatest value, very little known to the 
general reader. 

He states that the first attempt to construct a street of 
bituminous rock in Paris was made upon the Place Louis XV, 
opposite the church of Saint Roche. This pavement was 
about 0.15 m. (6 in.) in thickness, and was formed of frag- 
ments of quartz and of mastic of coal tar (bitume de houille) 
upon a bed of sandstone, the joints of which were filled with 
mastic. No date is given. These coal-tar streets, even with 
a concrete base, were not satisfactory. 

De Coulaine discussed bituminous mastics at length and 
insisted that they should consist of mineral tar and lime, to 
which sand and gravel may be added, but the choice of the 
tar and lime are alone of importance. 

He says, the tars melt completely at a little above 100 C. 
and give off vapors and boil at 120 to 140 C. As the distilla- 
tion progresses, the liquidity and elasticity of the bitumen 
diminishes, until finally there remains a brilliant black sub- 
stance very brittle at the ordinary temperature and decom- 
posed with great ease by prolonged heating. He says, the 
natural tar of Bastennes is quite different from coal-tar, which 
evaporates more rapidly, producing a brittle mastic, while 
the oils of the natural tar remain "fixed." He further states 
that sulphur made the mastics brittle, and observes that when 
lime is used in the preparation of mastic, it is preferable to 
use quick-lime reduced to an impalpable powder. 



*Annales des Mines; 3d Series; Vol. vi, p. 179, 1834. 

tAnnales des Fonts et Chausses, 2d Series; Vol. xix, p. 240, 1S,~0. 



HISTORICAL INTRODUCTION. 283 

He prefers the bituminous rocks found at Seyssel, Val de 
Travers and Lobsann, which are composed principally of 
carbonate of lime and bitumen, completely identical with the 
tar (maltha) of Bastennes, generally mingled in the propor- 
tions, nine parts of mineral to one of bitumen, as great diffi- 
culty was experienced in effecting a complete mixture of the 
tar and quicklime. He asserts that it is indispensable that 
the mastic fill such conditions that when used it will not be 
so hard as to lead to fracture, nor so soft as to receive impres- 
sions from heavy traffic. Another matter of importance is 
the concrete base, which should be thick enough to be un- 
yielding, and also that the proper season in which to lay 
bituminous rock streets is from May I to September 15. 

A careful examination of this paper shows that at its date, 
November 30, 1849, ten years' experience with bituminous 
rock streets had demonstrated the following points : 

That coal-tar was unfitted for the construction of streets. 

That quicklime in impalpable powder is to be preferred 
to a grit, however fine, made of pulverized limestone. 

That the natural bituminous limestones are superior to 
any artificial mixture of lime and bitumen either with or with- 
out sand. 

That for such purposes as require an artificial mastic, 
Bastennes tar or maltha, deprived of its light oils, is the best 
material with which to soften Seyssel rock. - 

That manipulation is of more importance than choice of 
materials, and that prolonged heating and overheating are 
especially to be avoided. 

Although De Coulaine nowhere uses the word maltha, he 
repeatedly uses the term mineral tar (goudron minerale), 
which is the equivalent for maltha as used by many other 
authors. 

In 1865 it was generally understood on the Pacific coast 
that the natural bituminous rock found at La Goleta, near 
Santa Barbara, Cal., containing about 50 per cent, sand, fur- 
nished a better material for paving than could then be made 
of any artificial mixture of sand with the purer asphaltum of 
that region. 

In the same volume with the paper of M. De Coulaine is 
the report of M. Ledun upon the "Asphalte of Auvergne," 



284 SOLID BITUMENS. , 

who laid a piece of what he calls "bituminous macadam" on 
the road from Paris to Perpignan in the department of Cler- 
mont-Ferrand. The report is dated February 29, 1852. This 
road was covered with crushed (molasse) natural bituminous 
sandstone, and compacted by use after the manner of an ordi- 
nary macadamized roadway. 

In 1861, M. Leon Malo, who had not long before been 
made the manager of the works at Seyssel, where bituminous 
limestone is mined and mastic prepared from it, published a 
memoir also in the Annales des Ponts et Chausses, which has 
since been published in book form and has become a classic 
upon this subject.* 

He says, the rock is prepared for use either by crushing 
cold or by decrepitation. When treated by the first method it 
is afterwards heated in retorts and mixed with hot bitumen 
to form mastic. When treated by the second method it is 
heated on iron plates. Or, it is heated in an apparatus an - 
alagous to a large coffee roaster, which, worked by suitable 
gearing was fed at one end and discharged from a trap near 
the other. The bitumen softens, and the mass falls to a pow- 
der which is sifted. As the powder cools slowly, it is carted 
from the decrepitator to the street in one-horse loads, which 
are spread by the workmen with rakes completely across the 
street. It is then rolled until cold. Nothing can exceed the 
simplicity of the operation. 

For the preparation of mastic the rock is crushed in a 
mill resembling a huge coffee mill, and heated on revolving 
cylinders, and thrown hot into pure bitumen heated to near 
its boiling point. The hot rock decrepitates, and a very inti- 
mate mixture is formed, which, after being heated and agi- 
tated during six hours, is allowed to cool in circular molds, 
forming masses in shape like a cheese. This mastic is strong, 
easily fusible and different from the original material. 
"Whatever be the action of the bitumen added, it is a con- 
stant fact that the closer the geological analogy between it 
and the bitumen with which the rock is impregnated the better 
is the mastic obtained." 

He condemns the use of candle-tar, coal-tar, and all other 

*Annales des Ponts et Chausses, Series 4, vol. 1, p. 69, 1861. L'As- 
phalte: Son origine, sa preparation, ses applications, par Leon Malo. Bau- 
dry & Cie, Editeurs, 15 Rue des Saints Peres, Paris. 



HISTORICAL INTRODUCTION. 285 

refuse material, in place of the pure natural bitumen, and re- 
marks, "that combination which is sought to be imitated in a 
cauldron by a mixture of a solid and liquid body without 
affinity for one another, is in the natural asphalt the result of 
one of those colossal operations of nature that man is inter- 
dicted from repeating." 

I wish to emphasize the conclusions reached by this 
eminent observer: 

That the bituminous limestone of best quality consists of 
a fine grained rock, in which each particle of mineral matter 
is enveloped, and separated from its neighbor by a cushion of 
elastic, adhesive bitumen. 

That want of care in heating the rock injures or destroys 
its valuable qualities. 

That in the preparation of mastic, the rock should be 
softened with natural bitumen as nearly as possible of the 
same kind and quality as that originally contained in the rock. 

That all attempts to prepare a substitute or artificial mas- 
tic of asphalt and coal-tar, or any other refuse material of 
similar nature had signally failed. 

These conclusions were reached at the beginning of 
1861. 

During the following twenty years streets were laid in 
Paris, London and other European cities, generally with sat- 
isfactory results. In 1880 William H. Defano, in London, 
Eng., read a paper before the "Institute of Civil Engineers" 
which provoked a lengthy discussion, to which further ref- 
erence will be made. 

The consensus of opinion reached by this symposium may 
be stated thus : 

That beginning at the bottom clay is a very, bad founda- 
tion for a street. 

That sand is but little better, both when wet throwing 
the concrete and asphalt, when invaded by frost, and therefore 
requiring to be drained. 

That lime mortar is worthless under asphalte. 

That hydraulic cement or lime is better, but not good. 

That 4 ins. of Portland cement concrete will sometimes 
answer, that 6 ins. is usually good, while 9 ins. under any 
circumstances will stand indefinitely. 



286 

That Seyssel or Yal de T ravers asphalte well laid, on a 
good concrete, well dried, is uniformly a success ; that laid on 
a concrete deficient in either thickness or quality of material, 
they will fail. 

That any asphalte may be ruined if overheated or laid 
on wet concrete. 

That as very good streets have been made of almost 
every asphalte known, it is fair to conclude that a good street 
depends more upon the materials and technique of the con- 
crete, and in the care and skill exercised in laying the as- 
phalte, than in the locality from which the asphalte is ob- 
tained.* 

The word "asphalte" in the above conclusions signifies 
the natural bituminous limestones found at Seyssel and other 
localities in Europe only. 

"ASPHALT STREETS." 

No very considerable amount, of what are known in Eu- 
rope as "asphalte streets," have been laid in the United States. 
In several cities of the Atlantic Coast, streets and squares have 
been, for various reasons, covered with imported Seyssel Rock. 
These constructions have usually been satisfactory in all re- 
spects except cost, which of necessity must be high, as com- 
pared with so-called sheet asphalt streets. The fine quality 
and durability of these constructions has very generally stimu- 
lated the desire to discover similar deposits on this side of 
the Atlantic. While bitumens in great variety are widely dis- 
tributed over the North American continent, the bituminous 
limestones and dolomites that resemble the rocks found at 
Seyssel and Neufchatel have been discovered but sparingly. 
An extensive deposit was reported some years ago to exist in 
Michigan, but nothing has been heard of it commercially. In 
the southern central part of Oklahoma, in Carter county, a few 
miles west of Ardmore, and farther north and east of Dough- 
erty, in Murray county, very extensive deposits of bituminous, 
dolomitic chalk,, soft and easily quarried, have been quite 
largely used for streets in Kansas City, Ardmore, Fort Worth 
and other cities of Texas. 



*Minutes of the Proceedings of the Institute of Civil Engineers, Vol. xliii, 

&276, 1876. Ibid. Vol. Ix, p. 109, 1879-80; Paving and Municipal Engineer- 
g, Vol. xi, p. 67, 1896. 



HISTORICAL INTRODUCTION. 287 

The rock has not been treated in the United States as it 
has been treated in Europe, nor is it used alone, but it is mixed 
in certain proportions with the bituminous sands and sand- 
stones, that are found in the immediate neighborhood of the 
limestones. For the Kansas City streets the two kinds of 
bituminous rock were ground together and mixed into a sort 
of mastic, at the mines, and transported to the street in large 
cakes that were melted and laid upon the streets. I have lately 
been told by persons familiar with the streets of Kansas City, 
that these asphalt streets, some of which were laid seventeen 
years ago, are now in just as good condition as when laid. 
These streets of bituminous rock exhibit a very marked su- 
periority over the so-called sheet asphalt streets that have been 
laid in the same city. 

In Ardmore, a number of streets have been laid in a man- 
ner more nearly approaching the method pursued in Europe. 
The material used was taken from quarries a few miles south 
of Ardmore, and were thoroughly mixed after being softened 
by heat. The material was spread on a concrete foundation, 
without a binder, and rolled until cold. When I inspected 
this street on one of the hotest days in August, it was solid 
as a rock. Neither horse's hoofs nor wagon tires made the 
slightest impression on it. I said to the City Engineer, You 
have very few six-ton loads on this street ; he replied, no, but 
we have traction engines, with corrugated wheels, and they 
do not make the slightest impression on it. I am told there 
are many others like it in the cities of northern Texas. I know 
of no such streets in any Atlantic or Pacific Coast city. They 
are the product of the intelligent application of sound princi- 
ples of technology, to the manipulation of the best materials for 
the construction of solid bituminous streets, yet found on the 
American continent. 

Natural roads of asphaltum; for short distances, had been 
known in southern California prior to my first visit there in 
1865, for an immemorial period. It was only a step from 
those to streets of asphaltic mastic, as there was an abundance 
of material with which to construct them at tide water on the 
coast above Santa Barbara.* 

*Geol. Survey of Cal. Geology, Vol. ii, Appendix, p. 60, 1882. 



288 SOLID niTi'MI-XS. 

I doubt if anyone now knows when this material was first 
used there for pavements. When I visited the locality in 
1866, I was told that the natural bituminous sand containing 
about 50 per cent of very fine quartz and pulverized shale, was 
much to be preferred to any artificial mixture that could then 
be prepared from a purer asphaltum and sand. Methods for 
mixing asphaltum and sand have been greatly improved since 
1866. Streets have been laid in the Pacific coast cities of 
bituminous mastic made with both the bituminous sandstone 
and asphaltum, w r ith varying success. Frost does not trouble 
them in that region, but the streets have, in some instances, 
been spoiled by laying in wet weather and from other causes. 
Having again visited that region in 1894, I am prepared to 
testify that the technology of asphalt paving, that has grown 
up there locally, has resulted in giving San Francisco, Santa 
Barbara, Los Angeles and other cities as good bituminous 
avenues and streets as are to be found in the average Ameri- 
can cities. 

There is no doubt that De Smedt laid the first bituminous 
mastic street that was laid in any Atlantic coast city, in front 
of the city hall in Newark, N. J., in 1870. He was a Belgian 
by birth and had learned the technique of bituminous rock 
pavement in Paris before he came to the United States in 1861. 
He ought to have known all that De Coulaine and Malo knew 
before he left Paris. There was no bituminous limestone, good 
or bad, to be had on the Atlantic coast. Even Trinidad pitch 
was very little known at that time. The Grahamite of West 
Virginia and Albertite of New Brunswick, with Cuban Chapa- 
pote, all nearly pure, hard and dry asphaltums, and of high 
cost, were practically all of the bitumens then available. 
There was no natural maltha, resembling Bastennes tar, to be 
had at any price, with which to soften these asphaltums. 
The only materials at hand were coal-tar, well known to be 
unsuitable, and the refuse of the petroleum refineries, that 
thirty years' experience in Europe had then proved to be but 
little better. 

It would be interesting to know the details of the history 
of De Smedt' s first pavement, just what went into it and how 
long it lasted. Between March i, 1870, and February 7, 1871, 
De Smedt took out several patents. An examination of these 



289 

patents shows that they cover the application of a well known 
process, which De Smedt must have learned in all its details 
in Paris, to new materials such as were then on the market in 
the eastern United States. It is not likely that he used eithei 
the expensive Grahamite or Albertite ; he probably used Trini- 
dad pitch and petroleum residuum the same materials that 
have since been used. 

Soon after, the successful laying of bituminous surfaced 
streets in Washington, D. C, led to their general use through- 
out the country. 



CHAPTER XVII. 
A MODERN STREET. 

A modern street consists of a concrete foundation upon 
which is placed a wearing surface to protect the concrete. 
The wearing surface may consist of bituminous rock, bitu- 
minous mastic or cement, bituminous block or wood block, or 
brick with bituminous joints. 

THE FOUNDATION. 

A suitable unyielding foundation should be constructed 
whatever may be the surface selected. The primary importance 
of an adequate mass and quality is self-evident. 

In a paper published in 1880, W. H. Delano discussed at 
some length the proper foundation for a bituminous rock 
street. He says, "The tradition is that sand is incompressible, 
that sand makes a good foundation for granite sets, and there- 
fore does equally well for concrete. Sand is incompressible in 
a cylinder, but under street traffic gets displaced and absorbs 
water, causing the concrete to crack. The bituminous layer 
follows and then unsatisfactory repairs are made, for repairs 
on a shifting concrete, through which the wet can rise, never 
last long." 

"In preparing the road of the Auteuil Bridge, Paris, a 
coating of liquid asphalt 5/8 in. thick was laid down to keep 
out the surface water from the masonry, then a 3~in. bed of 
sand by order of the government engineer, who feared lest 
the immediate contact of the rough concrete with the bitumin- 
ous mastic would damage this coating. On the top of the sand 
was put a layer of hydraulic lime concrete, and on top of the 
concrete 2 ins. of compressed Val de Travers bituminous lime- 
stone. The rain water filtered through the curbstone into the 
layer of sand ; in hard winters it froze and forced up the con- 
crete, and in summer the sand yielded under heavy traffic. 
In 1877 the roadway of the Pont Massena, Paris, was laid. 
Nine inches of Portland cement concrete was placed upon the 
liquid asphalt coating, and upon that 2*4 ins. of compressed 

290 



A MODEKX STRI-l'.l' 291 

Val de Travers bituminous limestone. It never moved, though 
subjected to heavy traffic.'' In 1875 the flooring of the Elbeuf 
bridge, Paris, was repaired. "This structure is of wrought 
iron, subjected to considerable vibration. The flooring is of 
Mallet's buckle-plates. Owing to the shape of the buckle- 
plates the hydraulic lime concrete was of unequal thickness, 
broke up under the vibration, and the asphalt of course fol- 
lowed. To meet the difficulty of the vibration, it was resolved 
to replace the hydraulic lime concrete with bituminous con- 
crete. The roadway was accordingly taken up, the old com- 
pressed bituminous limestone was heated until it fell to pow- 
der; it was then mixed with refined bitumen to make it into 
a mastic, to which 40 per cent of dry grit was added, and with 
every 2 parts of this asphaltic mortar, 3 of hot flintstone were 
mixed. This concrete was laid down hot upon the buckle- 
plates, and well rammed and dressed till a hard and slightly 
elastic surface was obtained. Upon this surface a layer 2 
ins. thick of compressed Val de Travers bituminous limestone 
was put down. The work was finished in October, 1875. Up 
to August, 1879, not a single repair had been made." 

A lengthy discussion followed Mr. Delano's paper. Mr. 
E. J. Harrison said that, "the first bituminous limestone road- 
way laid in the city of London, was laid in Threadneedle 
street in 1869. It consisted of 2 ins. of compressed Val de 
Travers bituminous limestone on a concrete foundation." It 
was, at the time he spoke, "within two months of II years old, 
and was then, as it always had been, in good condition." He 
said further, "he had been struck with the unanimity with 
which every speaker urged the necessity of a solid foundation 
for a good road. A bituminous limestone road was in reality 
a concrete road with a surface of bituminous limestone put 
upon it to carry out certain ends. If the concrete founda- 
tion were taken away or tampered with, or negligently laid, 
bituminous limestone itself would form a very sorry paving. 
For that reason, his company had always urged the desir- 
ability of laying a concrete composed of a quick-setting Port- 
land cement with the best obtainable ballast. The only failure 
he knew in Val de Travers roadways had been in the use of 
lime concrete under lime mortar, in Holborn opposite Gray's 
Inn. The specification prescribed about 9 ins. of lime concrete 



SOLID BITL'MEXS. 

with fa in. of lime mortar. When the concrete was ready to 
receive the bituminous limestone, a fire broke out in Holborn, 
the place was flooded with water, the engines drove over the 
concrete, and the population of Gray's Inn trampled it down. 
It was subsequently made good and the bituminous limestone 
spread. For five or six years the road was kept up at consid- 
erable expense, and then relaid. On removing the bituminous 
limestone, it was found that the lime concrete had never set, 
that the mortar floating had never adhered to the concrete but 
was mostly in powder, produced by the action of the rammers 
or by traffic afterwards." 

"Reference was made by several of the speakers to cracks 
both in the compressed bituminous limestone and the mastic. 
They were generally attributed to defects in the concrete, 
arising from various causes. They usually appear in severe 
weather. Coarse sand in mastic is objectionable and causes 
disintegration. Chabrier noticed that cracks appear in work 
laid in wet weather. Delano observed that if mastic was 
placed on wet concrete it would blister and sometimes crack. 
He believed that cracks in nine cases out of ten resulted from 
the concrete.'' 

Mr. Fogarty was of the opinion that if the concrete was 
laid almost dry and thoroughly rammed and jointed at inter- 
vals, the joints being left open until the water had evaporated, 
it might be covered with bituminous limestone without any 
fear of cracks, provided there was a solid substratum. But 
when it was laid upon clay, difficulties would invariably arise 
unless there was interposed between the concrete and the clay 
a considerable amount of hard, pounded, dry filling for drain- 
age purposes. The most difficult pavements were those laid 
upon a clay substratum, and he knew of no mode of curing 
the difficulty except by getting out a considerable depth of 
clay and replacing it by dry material." 

"Other causes of disintegration are due to deficient ag- 
gregation, which may arise from two circumstances, either the 
powder has been too cold when laid, or it has been overheated. 
Overheating bituminous limestone renders it as inert as sand. 
It is quite possible to make bad work with good materials, 
though the converse is not true. Still, when good bituminous 
limestone, properly prepared, and laid by skillful workmen, 



A MODERN STREET 



293 



does not stand, it is almost always the fault of the concrete." 
The consensus of opinion reached by this Symposium was 
stated on page 285. The gentlemen who expressed these opin- 
ions represented the experience and skill that had been gained 
by thirty years' practice in laying streets with Val de Travers 
and other bituminous limestones found in Europe. In the 
long quotation given above the word "asphalte" was used to 
designate these bituminous limestones which fall into a pow- 
der when moderately heated, that may be passed through a 
screen while warm without clogging the screen. 

This word "asphalte," spelled with a final e, is not equiva- 
lent in meaning to the word asphalt, used in the United States. 
Nor is any material called asphalt in the United States identi- 
cal with the bituminous limestone called "asphalte" and found 
and used in Europe. It is nevertheless a fact, that the con- 
sensus of opinion reached by these eminent and experienced 
technologists, applies equally to the foundations laid in the 
United States and to the surfaces prepared from natural solid 
bitumens, that have been laid upon them. It may be generally 
stated that good streets have been constructed from every kind 
of natural solid bitumen that has been used for the purpose. 
No such general statement can be made concerning the so- 
called "artificial asphalts" that have been named on a previous 
page (see page 204). It is quite certain that some of them 
are wholly unfitted for use in the construction of streets, and 
it remains to be proved that any of them are equally good 
when compared with natural solid bitumens. Excluding the 
so-called artificial asphalts that have been used in the United 
States as being uniformly of very varied and uncertain quality, 
the consensus of opinion reached by the symposium as stated 
on page 285 may be affirmed with equal force as being fully 
sustained by the experience gained in the United States, since 
1880. 

Indeed, it may be truthfully stated that successful street 
construction, no matter with what material the surface may 
be laid, on a concrete foundation, depends primarily on the 
stability and permanence of the foundation. The cement 
should be Portland cement of the best quality. No small 
economies should be thought of in this connection. No 
specious arguments that cheaper cements will, in time, set as 



2 y 4 SOLID BlTl'MEXS. 

strongly as Portland cement should be allowed a moment's 
expression. The first load that enters upon the street may 
be a maximum load of coal. Its entry cannot be delayed. It 
is no adequate test that the street is rolled with a lo-ton roller 
48 ins. wide giving about 250 Ibs. per lin. in. A 6-ton load of 
coal in a modern wagon is two-thirds on the hind wheel's, 
which may have a rim each 4 ins. wide, putting 8,000 Ibs. on 
8 ins., or 4 times 250 Ibs. to the lin. in. Nor for the same rea- 
son should any 4 in. concrete be laid, nor surfaces be put down 
on old Belgian blocks, rolled with a 48-in., lo-ton roller. Six- 
ton loads of coal test the stability of every street in our large 
cities, no matter whether they be residence streets or not. 
If 4-in. concrete or unstable Belgian block gives way under 
such a test the bituminous surface is sure to follow and a hole 
in the surface or both surface and foundation is sure to come 
in time. Inadequate foundations are also responsible for no 
inconsiderable portion of the damage from leaky gas mains 
and from the ascent of substructure water. To insure good 
streets the concrete foundation should be 6 in. thick, rigid, 
stable and impervious, hence cements that make weak and 
spongy mortars should be uniformly discarded. 

Clean, sharp, hard sand of properly assorted sizes to fill 
all the voids is an essential element in a first-class concrete. 
Mr. Clifford Richardson, in his Modern Asphalt Street, page 
28, has discussed the subject of sand in a manner that leaves 
little or nothing to be said. The reader is referred to his pages 
which are outside the purpose of this work. 

The stone should be clean, unweathered rock ; it matters 
little of what kind, so long as it is hard and free from weath- 
ered portions, that are easily disintegrated. The presence of 
rock masses that will crush more easily than the cement mor- 
tar, contributes to a weak concrete, even with the use of a 
first-class cement mixed with a first-class sand. 

There is no reason for supposing that a street founda- 
tion made of suitable materials and laid of proper thickness on 
a well drained substratum is subject, after complete setting, to 
deterioration or decay, if left undisturbed. The most potent 
cause of apparent failure of foundations, is street openings 
that have been carelessly or inadequately repaired. These 
openings frequently extend into the hitherto undisturbed sub- 



A MODERN STREET 295 

soils of the street, and involve a large part of its permanent 
stability. If they are not replaced as permanently solid as 
the original soil, a slow yielding of the support of the founda- 
tion until the foundation bridges open spaces, or follows the 
settling of the soil, is certain. The failure of foundations and 
surfaces after street openings inadequately filled and care- 
lessly repaired, is inevitable, and any surface, no matter of 
what material, will sooner or later follow such a foundation. 

SURFACES. 

The laying of surfaces of bituminous rock, chiefly lime- 
stone, as carried on in Europe, has been fully described in 
previous pages. In the United States so-called asphalt streets 
are laid with materials that require a technology in some re- 
spects quite different. The crude bitumen most frequently 
contains mineral or organic impurities, sometimes both, that 
have to be removed by refining. This is accomplished by 
slowly melting the bitumen at a low temperature and skim- 
ming the surface while the mineral matter is "allowed to sub- 
side. The refined material is drawn off above the semi-solid 
"bottom." 

The care with which this process of refining is conducted 
and the technical skill exercised are very important factors in 
determining the quality of the street surface that will be con- 
structed from the refined bitumen. Too much attention has 
been paid to the rival claims of the owners of different de- 
posits of natural bitumen and too little to the purely scientific 
questions involved, which are often fundamental and common 
to all varieties of bitumen alike. The technique employed by 
the engineers and the superintendents of paving plants where 
bitumens have been refined and paving mixtures compounded 
in the Unitd States, like that employed by the masters of the 
art in Europe, as described by those masters for more than 
fifty years, consists of processes governed for the most part 
by "rule of thumb." The details of the work performed in 
London and Paris, at a cost of thousands of pounds sterling 
and millions of francs, much of which has been repeated in 
the United States at similar cost, exhibits an amazing disre- 
gard of principles that appear to be fundamental. How engi- 
neers trained in the best technical schools of the world could 



SOLID B1TUMEXS. 

expect a lime concrete to set out of contact with the external 
air; or porous concrete made of natural cement and only 4 ins. 
thick, too protect or sustain 2 ins. of bituminous mixtures ; 
or any such structure, of whatever quality, to be made to stand 
over wet clay or sand invaded by frost, is simply marvelous. 
However, "rule of thumb" is primarily based on funda- 
mental chemical laws, that we may be too ignorant or too 
heedless to recognize ; yet, which, in their invariable action, 
make precedent and routine possible, and lend to methods 
learned by experience that exactness that makes empirical 
technology possible. It is true such knowledge is gained at 
enormous expense, but the great cities of Europe and America 
have paid the bills. The trouble is easily determined by 
perusing the papers from which I have quoted. The experi- 
ence gained since 1843 ' ls to-day just as heterogeneous a mass 
of empirical knowledge as it was in 1850 when De Coulaine 
published his little known, but valuable and interesting, paper, 
which seems to be unknown to the engineers of the United 
States. Not even a qualitative analysis, reaching final results, 
has been published, had upon any variety of solid bitumen 
known to the writer. No intelligent connection of mistakes 
has been-made and but few standpoints have been gained from 
which one could reach out after more accurate knowledge. 
Conclusions have been reached and expressed as matters of 
opinion, almost as many and variable as the individuals ex- 
pressing them.* It is therefore somewhat difficult to discuss 
from a scientific standpoint the practice that is followed in 
refining the different bitumens on the market. Considerations 
of business competition prevent any public demonstration of 
whether or no a hard and dry asphaltum heavily fluxed in re- 
fining, or a bitumen less hard and dry and moderately fluxed 
or a soft bitumen not fluxed at all, is the most desirable refined 
material with which to prepare asphaltic cement, as proved by 
actual use. Several facts appear, however, to be generally ad- 
mitted by those most conversant with this technology. First, 
that in the preparation of refined bitumen or of asphaltic ce- 
ment the bituminous flux shall be as free as possible from 
both solid and liquid paraffine. Second, that the bituminous 
flux shall be so completely blended with the solid bitumen 

*Paving and Municipal Engineering, xi, p. 218. 



A MODERN STREET 



297 



that when the melted mass shall be poured into water no 
separation and floating of the oil shall take place, nor when 
broken into fragments or slices should they produce an oil 
stain on paper. Third, that the conclusion reached by De Cou- 
laine in 1850, is perfectly sound to-day, "That for such pur- 
poses as require an artificial mastic, Bastennes tar or maltha, 
deprived of its light oils, is the best material with which to 
soften" any form of solid bitumen. As a substitute for nat- 
ural maltha, which is not everywhere available, the tar or 
dense residuum of the petroleum refineries is most frequently 
used. This residuum is a product of a variety of processes as 
carried on in different plants where different kinds of petro- 
leum are treated. There is great choice among them. The 
best is none too good and the poorest may safely be rejected 
as too bad ; the selection should always be made of that ma- 
terial that most nearly approximates in its qualities a natural 
maltha and will most completely blend with the solid bitu- 
men to be fluxed. 

The above remarks apply with equal force to the refining 
of crude solid bitumens and also to the conversion of the re- 
fined bitumen into so-called asphaltic cement. 

The bituminous mastic that is laid upon the street is made 
by fusing together asphaltic cement, stone dust and sand. 
The stone dust should be hydraulic cement or air-slacked 
quicklime sifted through a No. 10 sieve. If a cheaper article 
than quicklime is desired, finely powdered limestone should be 
used in preference to quartz, granite or trap rock. Limestone 
or, more especially quicklime, will correct any acidity in the 
bituminous surface mixture arising from any cause. Lime- 
stone, not carbonate of lime should be specified, as powdered 
white marble, which most nearly approximates carbonate of 
lime, is never used. 

Again De Coulaine's conclusion "That manipulation is of 
more importance than choice of materials, and that overheat- 
ing and prolonged heating are especially to be avoided," holds 
good to-day as in 1850. 

The French engineers had reached the conclusion that 
those streets should not be put down in wet or freezing 
weather. The water in and upon wet concrete remains 
hermetically sealed beneath the bituminous sheet and perma- 



2 9 8 



SOLID BITUMENS. 



nently prevents any adhesion between the two surfaces. The 
surface becomes very hot in summer and the confined water 
expands and some of it passes into vapor causing the soft and 
yielding; surface to buckle and slide on the surface of the con- 
crete. 

I have never been convinced that a binder course filled 
with cavities, into which traffic soon forces a portion of the 
surface mixture, is an essential or desirable element of a bitu- 
men surfaced street. 

I wish here to particularize the construction of two ex- 
ceptionally good streets that have come under my personal 
observation. 

On visiting- Washington, D. C, some years since, I made 
a careful examination of the general condition of the bitu- 
minous surfaced streets of that city. They have a deservedly 
very high reputation. A. W. Dow, then Inspector of Asphalts 
and Cements for the District of Columbia, showed me miles 
of the fine streets of the city and gave me such information 
as I desired. He told me he allowed the use of natural ce- 
ments for concrete foundations, although his principal assist- 
ant (who has since succeeded him) admitted to me 
that Portland cement made a stronger concrete, that 
is more solid and less likely to be penetrated by 
water from the subsoil. He also allowed the use of petroleum 
residuum from the western refineries and residuums made 
from California malthas and petroleums for fluxing natural 
asphaltums and Trinidad pitch. I asked him if he had al- 
lowed the use in Washington of any solid residuums of any 
kind of petroleum under the name of asphalt or asphaltum, 
and he replied that he had not. He showed me a few very 
old streets, that were the first, or among the first, bituminous 
streets laid in Washington. They were made of a preparation 
of coal-tar pitch and coarse gravel, which was laid very thick, 
forming a sort of bitumenous concrete. They were in fairly 
good condition though more than twenty years old. Among 
these streets I noticed Vermont Ave., from H St. to I St., laid 
of Trinidad pitch by the Cranford Co. in 1880, on a foot of 
this old bituminous concrete. The bituminous base was so 
thick that no moisture could get through it to the surface. 
Although 22 years old it was in excellent condition. 



299 

Several streets in bad condition also lent their testimony. 
Sixteenth St. N. W., had been down for 21 years, laid by A. 
L. Barber in 1881, was nearly one-half in broken patches worn 
down to the concrete base. Fifteen-and-one-half St., between 
the White House and the Treasury, had been down 8 years ; 
Trinidad Lake pitch on a concrete foundation. The ground 
is springy and moist, and the surface was disintegrating from 
the action of water on Trinidad pitch. On Executive Ave. 
the surface was laid of Trinidad Lake pitch. It had been 
down three years and was rapidly going to pieces (1902). 
According to Mr. Dow's report for 1899, "This pavement was 
laid on bituminous base (1889) and went to pieces very rap- 
idly, owing to the springy nature of the ground. In 1894 it 
was taken up, the ground underdrained, and asphalt on hy- 
draulic base laid ; the hydraulic base was paid for by the Dis- 
trict, the surface laid by Barber Co. free of cost." Mr. Dow 
assured me that no Bermudez asphalt surface laid in Wash- 
ington had ever ''rotted," not even in the gutters. 

One of the best bituminous surfaced streets ever laid in 
the United States was laid on Franklin Ave., Buffalo., in 1879. 
"The specification was 6 ins. of broken stone, rolled with a 
lo-ton roller, 3 ins. of binder composed of gravel and coal-tar 
pitch, 2 ins. of asphalt surface composed of sand, Trinidad 
asphalt and fine ground limestone. The asphalt was fluxed 
with what was known as paraffine still wax, or wax tailings, 
which come from residuum of petroleum distilled and was of 
a greenish yellow color. The proportions of mixture were 
about as follows : To a ^ cu. yd. box of hot sand (added to 
the sand before heating was y% part of fine limestone) I mixed 
25 gallons of asphalt and wax, which had been combined by 
a stone agitator. The wax was T /g part of the 25 gallons. The 
mass was roughly mixed by hand and then put through a 
long pug mill steam mixer this being before the modern im- 
proved mixer had been invented. The heat of materials was 
kept as near as possible to 350 and was carted about i l /2 
miles, and spread and laid at a heat of 250 to 300. The 
limestone was screened by screening crushed stone, there be- 
ing no facilities for grinding fine. The result was a large per- 
centage of particles from ^ in. down. These in after years 
showed plainly on the surface, but were held firmly in the 



300 SOLID BIT [\M1L\S. 

asphalt. We guaranteed the pavement for 5 years and there 
was no repairs required at the end of that time. The original 
pavement remained until a year or two ago, and has been con- 
sidered the best wearing pavement in the United States, so 
much so that several competitors have claimed it as their 
pavement. In 1895 I inquired of the Buffalo city engineer 
about the record of the pavement and he reported as follows : 

Laid in 1879 square yards, 7.264. 

Rapairs, 1887 $ 70.00 

Repairs, 1888 196.23 

Repairs, 1890 600.00 

Repairs, 1891 115.16 

Repairs, 1892 702.16 

Repairs, 1893 246.20 

Repairs, 1894 560.89 

Repairs, 1895 340.75 

$2,831,39 

Total cost for repairs per square yard $0.403 

Average cost for repairs per square yard per year, 16 years.. 0.25 

Considerable repairs necessary. He considered the serv- 
ice of the street remarkable. * In 1878 I laid the in- 
tersection of Jones and Eddy Sts., San Francisco, using Cali- 
fornia asphalt with wax mixture. I saw the pavement a year 
ago and it was in good condition."* 

These streets will be further discussed in succeeding 
pages. 



"Letter from N B. Abbott, und^r date Sept. 19, 1898. 



CHAPTER XVIII. 
BITULITHIC STREETS. 

The foundation for the bitulithic pavement should be 
made after careful examination of the character of the sub- 
soil or material over which the pavement is to be laid. If 
the subsoil is of a character, such as gravel, which can be 
rolled, a bituminous base is recommended. If the subsoil is 
spongy clay, or other material which cannot be rolled so as 
to provide a solid sub-foundation, a hydraulic concrete foun- 
dation is necessary. 

Where the street to be improved is now paved with 
macadam, stone blocks, cobbles or brick, on either a concrete 
or other suitable foundation, and the grade of the street will 
permit raising the grade about 3 ins., surfacing with bitu- 
lithic over the present pavement is recommended. The foun- 
dation of asphalt or other pavement may readily be resurfaced 
with bitulithic wearing surface, by taking care to thoroughly 
roughen the old smooth surface of the concrete by hand pick- 
ing or other means. 

The sub-foundation having been thoroughly rolled, the 
bituminous foundation for bitulithic pavement is made of 
broken stone or slag laid to a depth of from 4 to 6 ins. or pos- 
sibly more, according to the character of the subsoil and the 
traffic to which the pavement is subjected. The stone or slag 
is thoroughly rolled with a steam roller and then upon it is 
spread a heavy coating of bituminous cement. Or, an hy- 
draulic concrete foundation is mixed and laid in the ordinary 
way from 4 to 6 ins. in thickness, depending upon the strength 
of the sub-foundation. A concrete 6 ins. thick, made of the 
best Portland cement is recommended. In order that* the 
bitulithic surface may bond with concrete foundation, it is 
very important that the surface of the concrete be roughened 
after it is thoroughly tamped, but before it has become set, 
by spreading over the surface clean, broken stone that will 
pass a 2^2 -in. ring and remain on a i}/2 in. ring. This, should 

301 



302 SOLID B1TUMEXS. 

be tampecl for about half its depth into the fresh mortar. 
Then tamp with a small tamper (2x3 in.) with which depres- 
sions from j4 to }/2 in. can be made in the concrete. It will 
be readily seen that this method provides a rough surface to 
the concrete, affording a union with the bitulithic surface 
which smooth concrete would not provide. 

Before laying the bitulithic surface the concrete is care- 
fully swept; A considerable portion of the stone tamped into 
the concrete will then become loosened and its removal will 
leave depressions in the concrete into which the bitulithic sur- 
face mixture will be impressed ; the depressions thus formed 
giving the same advantages as the protruding particles of 
stone where they remain imbedded in the concrete. 

Upon the foundation is spread the wearing surface which 
is compressed with a heavy steam roller to a thickness of 2 
ins. The surface mixture is made of the best stone available, 
varying in size from a maximum of i or i l / 2 ins. down to an 
impalpable powder, the various sizes of smaller stone, sand 
and impalpable powder being provided to fill the spaces be- 
tween the larger stones. The proportions used of the various 
sizes of material are predetermined by physical tests with a 
view to obtaining the smallest percentage of air spaces, or 
voids in the mineral mixture, and vary with the character and 
shape of the particles of stone used in each particular case. 
After the proportions have been determined, the mineral ma- 
terial is passed through a rotary dryer, from which it is 
carried up an elevation and through a rotary screen which 
separates the mineral material into its different groups of 
sizes. The proper proportion by weights of each of these 
sizes is secured by a scale having seven beams, the exact 
required amount being weighed out, and run into a double 
shaft rotary mixer. Then it is combined with a bituminous 
cement which is also accurately weighed in the proper propor- 
tion. The whole is then thoroughly mixed together and 
dumped, while still hot, into carts, hauled to the street and 
spread as stated above and thoroughly rolled with a heavy 
steam roller. 

After the surface is thoroughly rolled, a flush coat of 
quick drying bituminous cement is applied to the surface, 
thoroughly sealing it and absolutely preventing the penetra- 



BITULITHIC STREETS. 303 

tion of moisture. There is then applied a thin layer of hot 
finely crushed stone, varying from j4 to ^4 m - m size, accord- 
ing to the roughness of the surface desired. The pavement 
is then again thoroughly rolled leaving the street in a finished 
condition. 

By using a coarse mineral grain (hard crushed stone), 
from i to i l /> ins., down to an impalpable powder, the voids 
are reduced to about 10 per cent and by completely filling 
these voids with a bituminous cement that is absolutely un- 
affected by water, a thoroughly water-proof and air-proof 
wearing surface is made which precludes the disintegrating 
influences of air and moisture. The attack can come only 
from the surface, and under these conditions is so slow as to 
give the pavement a very long life. The coarse grain also 
affords a gritty surface which gives a good foothold for 
horses. 

As the stone supports the traffic it is not necessary to 
rely upon the bituminous cement, to give the necessary rigid- 
ity to sustain traffic. The bituminous cement makes the 
pavement water-proof and binds the mineral ingredients to- 
gether so as to prevent the action of water and the picking 
out of these particles by the horses' hoofs. The cement used 
is so soft that the pavement will not crack in cold weather 
and as the stone itself sustains the traffic the softness of the 
cement is no detriment in summer. After five years' experi- 
ence in cold climates no bitulithic pavement has cracked in 
the slightest degree.* 

"Correspondence with Warren Brothers Co., by S. F. P. 



CHAPTER XIX. 

THE OILED ROADS AND STREETS OF THE 
PACIFIC COAST. 

These roads and streets are mainly the result of condi- 
tions prevailing in the southern counties of California. "Soon 
after the discovery of oil at Summerland on the southeastern 
coast of Santa Barbara county in 1894, oil was used in a small 
way in the immediate vicinity of the wells, the first applica- 
tion being made to the road surface of Ortega Hill, on the 
borders of Summerland. From that small beginning the use 
of oil on roads nas extended until it is the favorite method of 
that section for laying dust and making a good all-the-year- 
round road. In some cases the roadbed has been plowed up, 
harrowed, and leveled, and then the oil worked in with a 
spiked roller. In other cases it is sprinkled on the road where 
dust prevails and allowed to settle into the dust until it packs 
from the passing of wheels. Where there is no dust and the 
road is quite hard, sand is sprinkled on after the oil is ap- 
plied, to take up the surplus so that the surface will pack 
under the wheels. The best results have been secured by 
applying the oil when the surface of the road was covered 
with a sandy dust of not too great depth, about i in. being 
most satisfactory. In applying the oil there has been used a 
sprinkling cart with an apparatus regulating the flow of oil 
according as it is thick and heavy, or light and more fluid. 
Some of the country roads are oiled the width over which 
the sprinkler distributes the oil at one passage. When the 
travel is greater twice that width is sprinkled, making an oiled 
strip of perhaps 20 ft. in width. Sixty barrels will give a 
mile of road one application the width of the sprinkler, or 
from 100 to 120 barrels for double that width. The heavier 
the oil the more satisfactory the results from the same quan- 
tity. The interval allowed between the first and the second 
application of oil depends much upon local conditions, char- 
acter of the roadbed, etc. The first application should be 

304 



OILED ROADS AND STREETS OF PACIFIC COAST. 



305 



horotighly incorporated with the soil before the second is 
put on. Special attention should be given to where the soil 
is particularly loose, and larger quantities of oil applied at 
such points. Generally as much oil has been used 'on the 
second application as on the first, although after a second ap- 
plication under usual conditions the quantity may be reduced 
each time. It is seldom that more than a fourth application 
is necessary to produce good results. The oil is heated so 
that it will flow more readily from the sprinkler. It is no 
longer considered necessary to heat it so far as its effect upon 
the roadbed is concerned. The lighter the oil the less need 
for heating. It is generally heated by steam to 180 to 200 
F. at Summerland, but by the time it reaches the points of 
application to the roads in the vicinity the temperature has 
dropped to 125. As the oil that is not used in the neighbor- 
hood is usually heated to drive out the water found in con- 
nection therewith, there is little or no exra charge for sup- 
plying heated oil. The specific gravity of the Summerland 
oil is from 12 to 16 B. The expansion caused by heating 
depends upon the specific gravity of the oil and the quantity 
of water contained therein. It is said that a 10 per cent in- 
crease by expansion would probably be an average, although 
very much depends upon the quantity of water contained in 
the oil. The oil used in the vicinity of Santa Barbara is ob- 
tained at Summerland, 5 miles east of the city, and has varied 
in price from 40 to 60 cents per barrel of 42 gallons. The 
average cost per mile of applying to the road is about $15.00, 
estimating a haul of from 5 to 10 miles. As to the amount 
and frequency of subsequent applications, everything depends 
on the character of the surface soil. Various kinds of soil 
abound adobe, red clay, alluvial and sandy. If it be such 
that the oil forms by admixture with the sand a species of 
asphaltum pavement, an effect that has been noted in some 
instances, then the road is easily kept in order. If, however, 
the oil does not readily amalgamate with the soil, and the 
passage of vehicles tends to break up the surface into small 
particles, then the oil must be applied until a good wearing 
surface is obtained. The most troublesome natural disad- 
vantage encountered in maintaining oiled roads in good con- 
dition has been the lack of homogeneity in the soil, some 



306 SOLID BITL'MEXS. 

being hard and some soft. The more nearly the road surface 
is made homogeneous the better are the results from the ap- 
plication of the oil." 

"When the soil is very sandy, through the use of a large 
quantity of oil excellent results are produced. By using a 
fine gravel with the oil a better road is secured with less oil. 
Where there is so much loose sand, in some places it is almost 
impossible to get enough oil in it to keep it from breaking 
up under the passage of heavy teams and vehicles. It has 
been demonstrated that it is less expensive to make the road- 
bed solid by graveling than to build it of sand and oil. It 
requires only about one-fourth as much oil to make a good 
road when a gravel base is provided as it does to make a road 
entirely of sand and oil. The gravel base, if properly con- 
structed, withstands the wear and waste by heavy traffic and, 
with additional applications of oil, as the volume of travel 
requires, develops a permanent surface, more substantial, and 
in less time, than in the case of roads built upon the natural 
sand alone." 

"In the first stages of the experimenting with oil sprink- 
ling, there were objections by some people to this method of 
improving the highways, because of the fact that when the 
oil was first applied it rendered the road disagreeable to trave! 
on, and had a tendency to soil vehicles and clothing. This, 
however, proved to be of only temporary duration, as a few 
days, when the oil had been properly worked in and the sur- 
face smoothed and packed by thorough rolling, sufficed to 
harden the surface and keep it clean. It was soon realized 
that the inconvenience caused by the first application of oil 
was not nearly so great as was caused by the first application 
of gravel. In the latter case it requires nearly a year for the 
road to become packed and smooth, while with oil the time 
required to put the road in readiness for easy and dustless 
travel is only a few days. Oil has the advantage over water 
in the fact that where applied there is absolutely no dust, and 
when the roadbed is properly prepared there is practically no 
mud during the rainy season. In the matter of expense, as 
compared with watering roads to keep down dust, the use of 
oil has also a decided advantage.'' 



OILED ROADS AND STREETS OF PACIFIC COAST. 307 

"The White and the Glover road-oilers are used. On the 
whole, the roads so far have not been affected by storm 
waters. Summer heat has been detrimental in a few in- 
stances, and rows of shade trees are regarded as a benefit." 

"The city of Los Angeles began oiling streets in 1901. 
The soil is generally gravelly, in some places black loam, in 
others sandy loam. The oiled streets vary from 30 to 60 ft. 
between curbs and in most cases are oiled the full width. The 
blocks vary from 400 to 600 ft. square. In preparing the 
street for oiling, the surface is brought to subgrade and cov- 
ered with a layer of gravel 5 ins. thick, after thorough rolling 
while moistened, containing no stones larger than 2 l / 2 ins. in 
diameter, and well rammed i ft. in width along gutters and 
curbs. On this is spread a top layer of gravel, 3 ins. thick 
after rolling and packing as before, containing no stones 
larger than i in. in daimeter. The entire surface is then 
broken and stirred to a depth of 2 ins. by a fine-toothed har- 
row. Oil is then applied, usually at the rate of i to i l / 2 gal- 
lons per sq. yd. At least 12 hours, usually 24, are allowed to 
elapse, when the surface is again harrowed and a second coat 
of oil put on, the quantity being proportioned so that the 
total amount used for the two applications shall not be less 
than two gallons per square yard of street surface. Places 
where an excess of oil occurs are sprinkled with sufficient 
sharp sand to absorb the same, and portions which appear 
too dry receive a further light application of oil. The oil used 
is crude petroleum from the Los Angeles wells, of specific 
gravity 11 to 14 B. and costs 65 cents per barrel at the tank. 
It is heated by steam to 180 F. for both applications. The 
cost of making the first application, in addition to the cost of 
the oil, is about $200 per mile. Chuck-holes are the principal 
trouble dealt with in maintaining the oiled streets, which re- 
quire some reoiling, according to condition -each year." 

"The experiences of forty counties, extending from 
Tehama on the north to San Diego on the south, a distance of 
600 miles, cover the subject thoroughly. In the beginning, 
oil was used as a substitute for water to lay the dust of roads 
more cheaply. Its efficiency for this purpose was quickly 
recognized, and through the hardened and lasting surface ob- 
tained, road-makers were led to its use in making permanent 



300 SOLID BITUMEXS. 

road surfacing. It is along this latter line that such remark- 
able success has been attained. Undoubtedly the work of the 
future will be the developing of oil surfacing to the point 
where can an artificially bitumen-covered roadbed will be had." 

"Careful work should be had in the preparation of a road 
that is to be oiled. If an earth foundation is to be dealt with, 
it should be worked until a uniform density is obtained. In 
the case of macadam or graveled roads, they should be smooth 
and free from weak and wornout spots. No one would think 
of laying an asphalt pavement without first obtaining a firm 
and uniform foundation." 

"In the application of the oil to any surface no pains 
should be spared to get an equal distribution, and a liberal 
sanding to hold the oil in place on the crowned surface. 
Again, the sand not only retains the oil in position, but is in 
corporated with and thus gives the real body to the contained 
asphaltum. The bearing power of the surface is greatly en- 
hanced by the proper saturation of sand with the oil." 

"The effort in securing a good foundation, properly grad- 
ed and drained, and the careful application of oil and sand. 
will be amply repaid in a good road."* 

The preceding pages, quoted from the Official Bulletin of 
the Department of Highways of the State of California, are 
not without value to roadmakers in other sections of the 
country. The insistence with which a good foundation, prop- 
erly graded and drained, is demanded is to be especially noted 
and regarded. While it is not to be asserted that oiled roads 
cannot be successfully constructed in regions subject to frost, 
it is not likely that they can be constructed in the same man- 
ner as they are constructed in California where frosts suffi- 
ciently severe to disturb earth foundations are unknown. 

Moreover, it must again be borne in mind, and never for- 
gotten, that the petroleum oils of California are created of 
such a peculiar composition that when exposed to the atmos- 
phere, by evaporation and chemical reactions, they are con- 
verted into asphaltum. It would, therefore, be expected that 
from natural causes a roadbed of sand, saturated with Cali- 
fornia petroleum, would become a roadbed covered with a 



"Oiled Roads of California. Bulletin No. 2. October. 1904. 



OILED RO.ins AND .STAV:7:7\9 OF PACIFIC COAST. 309 

solid bituminous concrete, especially if the sand was mixed 
with gravel. It would therefore, again, be a fatal mistake to 
suppose that a roadbed saturated with any of the petroleums 
found in the Mississippi Valley, which never form asphaltum 
from natural causes, either by evaporation or chemical 
changes, would ever become covered with a sheet of solid 
bitumen, wherever it might be constructed. 

The 'only attempt to construct such a road within my 
personal knowledge was made in the summer of 1906, on one 
of the state roads being constructed a few miles west of 
Wickford, R. I. The new roadbed has been sprinkled with 
crude petroleum. The result was inappreciable, except that 
the road had the odor of crude petroleum. A similar oiled road 
was observed between Pittsfield and Lenox, Mass., in August, 
1908, and others in that neighborhood in 1909- 

Petroleum has also been used in California to lay the dust 
on the road beds of railroads in place of ballast. Several ap- 
plications are necessary. The oil serves an additional purpose 
of killing the weeds along the track. Both the great railroad 
systems of California, the Southern Pacific and the Santa Fe, 
have used oil with satisfactory results. 



CHAPTER XX. 
ASPHALT BLOCKS. 

Asphalt blocks consist of a aggregate of crushed stone 
cemented together with bitumen under great pressure in the 
form of large bricks. The molding is done in machines in- 
vented for the purpose, of which there are several that differ 
more or less in mechanical construction. The best machine 
is the one that with the least expenditure of power will make 
the most compact blocks of the most uniform size ; both of 
which properties are essential elements of good blocks. 

Experience has proved that a hard unweathered trap rock 
or limestone or cement rock, or a rock that will make neither 
good lime nor good cement, but is both hard and tough, and, 
like trap rock, is only slightly crystalline, is most suitable. 
Very much depends upon the crushing of the stone. It should 
be angular and not flaky. This consideration is one that gives 
trap rock its superiority over almost every other rock. The 
parallel bedding of the trap has been destroyed, and, unlike 
rocks that are not metamorphosed, its fracture is angular. 
It is very important that the sizes of crushed stone should be 
graded, from the largest size, to an impalpable dust, in such a 
manner that while about 70 per cent of it will pass a circular 
hole y in. in diameter the different sizes should very closely 
approximate those in the following table. The sizes that will 
not pass a *4-in. hole should contain very few pieces half an 
inch in dimensions, and there should be none larger. 

Table of Dimensions of Crushed Stone. 

Percentage 

for 
Sieves. test voids. 

Passing 200 meshes to linear inch 11.4 

Passing 100 meshes to linear inch, retained on 200 3.0 

Passing CO meshes to linear inch, retained on 100 5.5 

Passing 40 meshes to linear inch, retained on 60 5.5 

Passing 30 meshes to linear inch, retained on 40 5.2 

Passing 20 meshes to linear inch, retained on 30 7.1 

Passing 16 meshes to linear inch, retained on 20 4.1 

Passing 10 meshes to linear inch, retained on 16 13.0 

Passing Vs meshes to linear inch, retained on 10 16.2 

Passing V meshes to linear inch, retained on % 29.0 

310 



ASPHALT BLOCKS. 3, , 

Any deficiency in the smallest size can best be filled with 
a cheap quality of hydraulic cement or with powdered quick- 
lime, either of which will c6rrect any slight acidity in the 
asphaltic cement or residuum oil. 

The proportions of asphaltic cement and stone are 
weighed out and thoroughly mixed in a mixer, where they are 
automatically passed to the molding machine in amounts 
just sufficient for a single block. The size of the blocks is 
12x5x3 ins., with an allowed variation of % in. This varia- 
tion gives a maximum deviation on the line of jointing of y 2 
inch, which is twice as much as it ought to be, as the writer 
has found a maximum variation in blocks made by the same 
machine to rarely or never exceed 1/8 inch. 

The proper laying of the blocks is edgewise, presenting 
a single surface of 12x3 ins. They are, however, often laid 
flat, presenting a single surface of 12x5 ins. Mistaken ideas 
of economy prompt this latter procedure, in which the dan- 
ger of breakage under unusual strain is enormously increased. 
The blocks are properly laid on 6 ins. of Portland cement 
concrete, with a cushion of sand between the surface of the 
concrete and the blocks. 

An unyielding foundation is an imperative necessity to 
insure a durable asphalt block street. 

The best asphalt blocks have been made, so far as the 
writer is informed, of well refined Trinidad pitch, fluxed and 
thoroughly blended with residuum oil that contains little or 
no crystallizable paraffine. The bitumen, when removed from 
the mineral aggregate by solvents, should be soft, very 
viscous and adhesive at ordinary temperatures. It should not 
be brittle at any temperature to which the street is likely to 
be subjected under traffic. No hard and fast rules can gov- 
ern such requirements, as they vary and should be determined 
for each locality. It should always be borne in mind that the 
bitumen holds the stone together and that the stone, not the 
bitumen, receives the wear of traffic. The bituminous aggre- 
gate, therefore, should be soft, tenaceous and adhesive, rather 
than hard, tending to brittleness, and while sufficient in 
amount should not be excessive. It is a mistake to suppose 
that a poor quality of bitumen can be compensated by in- 
creasing the amount. Good blocks cannot be made with 



312 



SOLID BITUMENS. 



either stone or bitumen deficient in the required qualities. An 
excess of such bitumen aggravates the evil. 

Good asphalt blocks, properly laid, make a clean, durable 
and very satisfactory street. 



CHAPTER XXI. 
WOOD BLOCKS. 

Wood blocks are prepared for pavement by sawing rect- 
angular blocks, from sound heart wood timber, 3^ in. (par- 
allel with the fiber), by 3 4 ins. by 6 10 ins. All of the blocks 
used on a single contract must be of the same kind of timber 
and of the same width. 

These blocks are treated in a vacuum apparatus with an 
antiseptic and waterproof mixture consisting of heavy oil of 
coal-tar mixed with rosin. The proportions vary. The mix- 
ture should be very fluid when hot and wholly free from solid 
matter that would gather upon the exterior surface of the 
blocks and prevent the complete saturation and impregnation 
of the blocks with the fluid mixture. 

The blocks are placed in an air-tight cylinder in which 
heat is raised and maintained at 215 F. for a sufficient length 
of time to insure the heating of the entire mass. The time 
will depend upon the size of the cylinder. The heat is then 
raised to 285 F. and maintained at that temperature until 
the blocks are completely sterilized. Application of heat is 
then stopped and the temperature of the cylinders allowed 
to fall until it has been reduced to 250. _A vacuum pump is 
then applied until the entire mass within the cylinder is com- 
pletely deprived of both water and air, or until the vacuum 
is at least 26 in. When it is absolutely certain that every 
block in the cylinder is free from water and air under as com- 
plete exhaustion as the apparatus is capable of producing, 
not less than 26 ins., the bituminous mixture is run into the 
cylinder at a temperature of 175 to 260 F., after which 
hydraulic pressure, of not less than 200 Ibs. per sq. in., is 
raised and maintained until every block is completely saturat- 
ed with the mixture. 

There are several important factors to be regarded in the 
successful use of this process for this purpose. 

First, the vacuum pumps must be of a size somewhat in 
excess of the theoretical maximum required. 

3*3 



314 



SOLID BITUMEN*. 



Second, not a single step in the process can be success- 
fully performed in haste. No matter what the size of the 
pumps may be in proportion to the size of the cylinder, the 
successful heating of the mass of blocks in a large cylinder, 
and of the complete removal of the vapor of water and air 
under a continued vacuum of 26 ins., requires time, and I 
have no doubt that it will be found in practice that there is a 
limit to the profitable operation of large apparatus. 

Third, complete saturation of all the blocks that go into 
a street, no matter what kind of wood may be used, is the 
critical consideration in the preparation of wood paving 
blocks. Any kind of wood completely saturated is to be pre- 
ferred to the most desirable wood only partially treated. I 
have examined blocks made of every kind of wood used in 
New York City and treated with every kind of oil used for 
that purpose. I have found among the different samples, 
blocks only smeared outside with oil and completely wet with 
water inside ; also, blocks fully saturated with light oil, and 
also with the heaviest oil used. It is absolutely impossible to 
drive oil by any amount of pressure into the pores of wood 
filled solid full with water. The water and air must first be 
driven out before the oil mixture can be driven in. The time re- 
quired for heating and exhausting must be determined for each 
apparatus separately, and it should be done with the greatest 
care. 

Fourth, the wear of traffic is borne by the wood and not 
by the bitumen with which it is saturated. The bitumen 
preserves the wood from decay. If on an average one-third of 
the blocks are filled with water instead of bitumen, it need 
occasion no surprise if street surfaces where such blocks are 
laid soon become conspicuous failures, from the presence of 
decayed blocks. 

Fifth, all timber should be seasoned under cover and then 
kiln dried, to avoid checks and also to reduce the time to its 
lowest terms required to pump out the vapor of water. 
Checked blocks should be avoided, because the checks make 
the blocks weaker, and also because it is quite difficult to fill 
the checks completely, with the oil mixture. 

A good wood block street is very good indeed, but when 
it is bad it is horrid. 



CHAPTER XXII. 
CONCLUSIONS. 

A careful perusal of the foregoing pages leads to several 
conclusions that express fundamental truths. They may be 
briefly stated as follows : 

First, that all bituminous streets and roads require as a 
fundamental prerequisite a solid, unyielding foundation, 
either of rolled and tamped soil, that has no soft spots, or, 6 
ins. of concrete, made of the best Portland cement mortar, I 
part cement to 3 parts of clean, sharp sand, the mortar to be 
mixed with 5 parts of clean, unweathered broken stone. No 
more false economy can be indulged than to make a founda- 
tion of natural cement mortar, soft, weak, and porous ; or, to 
use soft, weak, weathered stone that has not the strength of 
the cement mortar. Nor should repairs be allowed so care- 
lessly made as to replace concrete with that which is weaker 
than that originally put down. Such grave mistakes are pro- 
lific sources of dissatisfaction with bituminous streets, in 
which city officials and citizens share an equal loss, both in 
money and temper. 

Second, the source from which the bitumen is obtained is 
of little concern, provided it be suitable ; that is to say, it shall 
be either protected from water or not acted on by water. 

Third, the concrete should be swept clean and as dry as 
possible, with preferably a rough surface. Before laying the 
bituminous surface, whether it be wood block, asphalt block, 
bitulithic or "sheet asphalt" it is not enough that the con- 
crete be swept clean, but it should be dry as well as clean. 
The water in or on a wet, cold concrete, whether frozen or 
not, cannot escape after the bitumen is put down. It remains 
to prevent the adhesion of the concrete surface with bitumen. 
If they do not adhere, the water expands under the heat of 
summer and assists the movement of the sheet of bituminous 
surface mixture from the center of the street to the curb. If a 
binder is used it becomes embedded in the surface mixture 

315 



and moves with it. A moving surface rolls, wrinkles and 
blisters, finally breaking beneath traffic, cracking in extreme 
cold and breaking down to the concrete. It is a fatal mis- 
take to lay bituminous surfaces of any kind in wet, cold or 
frosty weather or before the surface of the concrete has thor- 
oughly dried out. Hot, clear weather is the time in which to 
do such work. 

Fourth, a binder course an inch in thickness which evens 
up the inequalities of the cement, that is made of stone of 
nearly uniform size, from which the fine particles have been 
screened, and consequently is full of holes, is of very doubt- 
ful value as a part of a bituminous street. If laid at all, it 
should be laid on a solid concrete impervious to water from 
any source. It should be free from voids, by grading the sizes 
of stone precisely as they are graded for asphalt blocks, using 
the bitumen, not to coat, or smear the surfaces of compara- 
tively large pieces of stone with large spaces of void between 
them, but to completely fill the small percentages of voids 
that remain between the fragments of stone graded for "least 
voids." Such a binder might be laid on dry concrete with a 
very soft bitumen that is not affected by water and thus form 
a solid protection to an immovable asphalt street mixture, 
that like bitulithic would only be attacked by the atmosphere 
from the surface. 

In the judgment of the writer, an unfortunate lack of techni- 
cal skill and appreciation has been exhibited in the con- 
struction of binders. All sorts of mineral and bituminous 
rubbish have been found in some of them. They have been 
laid with such a large proportion of voids that traffic has soon 
forced the surface into the binder until the whole mass was 
but little more than 2 ins. thick and had every appearance 
that the bitumen of the binder had been absorbed by the sur- 
face, leaving the dry binder stones almost loose and with lit- 
tle or no adhesion to the concrete. Such a binder is no binder 
at all, and in the judgment of the writer, is worse than noth- 
ing. 

Fifth, the mineral aggregate of the wearing surface 
should be a hard, sharp sand that should all pass a No. 10 
screen and should be graded in such sizes as will insure least 
voids. If the sand is deficient in fine rhtst passing a 2OO-mesh 



CONCLUSION. 317 

sieve, the proper amount should be added in a good quality 
of natural cement, though Portland cement would be better. 
The term "inorganic dust," under which all sorts of soil, clay, 
weathered screenings and inorganic rubbish, that will absorb 
water, have been specified, has no place as designating an in- 
gredient of a wearing surface. 

The bitumen should be selected with reference to the 
climate of the locality where the street is to be put down. So 
much depends upon what is put under a street surface that 
no hard and fast rules can be laid down to govern such selec- 
tion. The opinion has been generally advanced that Franklin 
avenue, Buffalo, N. Y., owed its lasting qualities to wax 
tailings, but streets have been laid of Trinidad pitch that were 
not fluxed with wax tailings, that were both very satisfac- 
tory and very unsatisfactory. It, however, must be admitted 
on Mr. Abbott's description that the surface mixture on 
Franklin avenue was underlaid with a waterproof binder, that 
it is highly probable had as much, if not more, to do with the 
permanance of the street than the wax tailings. If I had the 
3 ins. of waterproof bituminous concrete on an immovable 
base that was laid on Franklin avenue, I would not hesitate 
to put on it any surface that had proved elsewhere to make a 
good street. There is no question that a residuum oil 
that is as free as possible from solid paraffine and 
paraffine oils is suitable for use as a flux about in propor- 
tion as its properties approach those of wax tailings. Never- 
theless, a good asphalt street results from the concurrence 
of a number of requisite conditions, and the absence of any 
one of them may cause disaster, when all the others are pres- 
ent. 

The conclusions herein expressed have been reached with 
regard to only one result, and that is a good street, with the 
conviction that the cheapest is not always the most econom- 
ical, nor is the lowest bidder always to be preferred. 



INDEX OF SUBJECTS. 



Page 

Acetone 

...102, 146, 148, 151, 152, 187, 194, 206 

Analysis by 152 

Albertite 17, 43, 77, 80, 288 

Acid, Acetic, Glacial 205 

Alcohol, Action of 93 

Amyl 149 

Benzine Tests 200,211 

Ethyl 150 

A.mber 107, 103 

American Chemical Soc., Lehigh Val- 
ley Section 232, 235 

Society of Civil Engineers 218 

Asphalt 81, 89 

Artificial 65, 66, 160, 204, 205 

Determination cf 204, 205 

Bitumin 65 

Blocks 310 

Natural 66, 67, 68 

Roads cf 287 

Petroleum 66, 67, 68 

Rock streets, in London ' 291 

in Paris 290 

Streets cf Washingt-m D. C 298 

Asphalte 4, 79, 80, 286, 293 

Asphalt en e 

70, 95, 9S, 99, 1C2, 106, 149 155,158, 

161, 162, 166, 171, 185 

A sphaltic coal 77 

Asphaltite 80 

Asphaltum 77, 79 

at Asphalto 16, 159 

California 159 

Cuba 158, 164 

Egyptian 152, 159, 189 

Montague Co., Texas 170 

Oklahoma 170 

Balanced filters 190, 192 

Basic Oils, Nitrogenous 43 

Bastennes Tar 297 

Benzene 153, 157 

Benzole 214 

Binder 298/316 

Bisulphide of Carbon 

65, 148, 158, 163, 173, 178, 187 

Bitulithic Streets , 301 

Bitumen, 

Analysis of. Apparatus for 186 

By Benzole 152 187 

By Carbon -tetrachloride. 70, 182, 19 1 

By Solvents 146, 183, 187, 194 

By Methods of Dow 171 

Engler 154 

Holde 153 

Linton 154, 165, 168, 186 

Richardson 131 177 

Sadtler 151 

Artificial 66 

By Metamorphism 

28, 31. 33, 48, 50, 53, 58, 60, 61 

Classification of (12, 76 

Definition of 1 , 80 

Ductility of 274 

Apparatus for 275 



Page 
Bitumen- 
Factitious 148 

Flow, Determination of 274 

Geological Distribution of 19, 36 

Bible Lands 1 

British West Indies 17 

California 12 

Colorado 9 

Cuba 18 

Europe-Asia 19 

Kentucky 11 

Mexico 18 

Missouri 11 

New Brunswick 17 

Oklahoma 11, 85 

Utah 10 

Veins 7, 8, 9 

In trap 7 

Venezuela 18 

Insoluble Organic Matter 179 

Mineral Matter in 148, 171, 179 

Natural Adulteration of 266 

Derivation of 82 

Of Athabasca River 17 

Bastennes 55 

Bechelbronn 91, 92, 95, 96, 207 

Coxitambo 96 

Dead Sea 2, 92 

Lobsann 92 

Neuf chatel 281 

Payta 92 

Uvalde Co., Texas 142, 143 

Organic Matter of 148 

Origin of 21 

Penetration of 275 

Apparatus for 277 

Physical Properties of 262 

Technical .^ 148 

Bitumen, pure.. 65 

Softening Point of 262 

Apparatus for 

263, 264, 266, 267. 268, 272 

Method of "Aktien Gesellshaft 

Erdolindustrie," f. Teer u 271 

With Cylinders 267 

Pitch Stick 267 

With Tubes, bent 26S 

Straight 271 

With Tubes and Cone 269 

Solution in Naphtha 175 

Spectra of 207, 208, 209, 210 

Bituminous Blocks 212 

Concretes 212, 213 

Mastic 284 

Rocks 197 

Streets. Concrete for 315 

Foundation of 315 

Boghead Mineral 2 

Brimstone 108 

Bromine Absorption Test 173 

California Asphaltum 104 

Petroleum 43, 99, 109. 150,184 

Maggots in 124 

Nitrogen in 40, 125 

Nitrogenous Bases in 125, 126, 127 



319 



INDEX ()! SUBJECTS. 



.245, 246, 



249 
254 
238 
257 
260 
240 
253 
251 
253 
252 
252 
248 
250 
247 
248 
245 
253 
217 
237 
239 
254 



Candle -Tar 7 

Cement, Analysis of 244 

Carmichael's Scheme 

Blount's Scheme 

Hillebrand's Scheme 222, 223 

Humphrey's Scheme 

Peckham's Scheme 

Richardson's Scheme 

Ultimate 239, 

Briquettes. Analysis of 

Coal Dust in 

Concretes. Analysis ol 217, 

Proportions of 258, 

Constitution of 

Determination of Alkalies in 

Alumina and Ferric Oxide in.... 

Carbon Dioxide in 

Lime in 

Magnesia 

Residue in 

Silica in 

Solution of 

Soot in 

Volatile at a red heat. 

Sulphuric Oxide in 

Examination of 

Fineness of 

Fuel Asli of 

Improved 

Mortars, Examination of 

217, 250, 256, 259 

Neat 255 

Newburry's Formula for.. 241, 242, 261 

Sample. Selection of.. 245 

Chemistry, the, of Solid Bitumens... 90 

Chloroform 103, 146, 162, 163,187 

Precipitate 103 

Soluble 1 03, 104, 105, 171 

Chocolate Pitch 105 

Cincinnati Anticlinal 40 

Coal 77, 249 

Gas 78 

Oil 38, 75, 78 

Coal Oil from Devonian Pyroschists. 39 

Trinidad Pitch 39 

Tar 206, 208 

Coke 59 

Cracking 39, 87 

Creosote Oil 194, 215. 217 

Apparatus for Determination of... 315 

Derivation cf Bitumens 

Artificial S7 

Bituminous Rocks S5 

Dippel's Oil '. . 43 

EpurSe 188 

Eschka's Mixture 114, 115 

Ethyl Ether 146. 187, 194 

' Factice . 78, 88, 197, 209 

Feldspar 79 

Fixed Carbon 77, 196 

Franklin Avenue. Buffalo. N. Y.299, 317 

French Schist Oil ; . . 2 

Fuming Sulphuric Acid Test. 198, 199, 209 

Gas Wells, Pressure on 59 

GilsoJiite 9, 47, 77, 79, 80 

Glance Pitch 5, 77, 105, 106 

Gooch. Crucible 151, 175, 176 

Grahamite 

2, 7, S, 43, 47, 77, SO, 159, 171, 288 

Huston-Grandeau Method for Deter- 
mination of Humic Acid 136 

Illuminating Oil from Lime-soap. . . . 41 
Illuminating Oil from Boiling Lin- 
seed Oil 41 

Tnspissation 82 

International Association for Testing 

Materials 6?. 70 

Iron Pitch 170 



Page 

Jew's Pitch 108 

Jonathan Watson's Deep Well 51 

Karg Gas Well 57 

Kentucky Rock 11. 159 

Kuban Residuum 158 

Lignite 77 

Lima Petroleum 43 

Maberyite 40 

Maltha 76. 77, 80 

Athabasca River 17, 152, 189 

California 159 

Malthenes, Character of 70, 181 

Melting Point 72 

Memoir on Composition of Bitumens. 91 

Methods of Distillation 149 

Methyl Alcohol 153, 187 

Microscope 206, 211 

Mineral Aggregate 212, 316 

Sizes of 310 

Modern Street 290 

Munjack IS 

Naphtha, of Amiano 41 

Definition of 80 

Soluble 179 

Xaphthenes 43, 44 

Natural Gas 76, 80 

Naphtha 76 

Nigerite 10 

Nitroderivatives 153 

Nitrogen. Determination of 142, 191 

Oil Field in Archean Time 59 

Roads and Streets of Pacifie Coast. 304 

Construction of 306 

Oils. Scotch Shale 43 

Olefines 44 

Organic Matter not Bitumen 

140. 171, 185, 191, 193 

Orpiment 10S 

Oxygen 43, 10S 

Determination of 107 

Estimated by, Difference 128 

Ozark Uplift 51 

Ozocerite 10 

Paraffine 44. 78, 83. 155, 202 

Determination of 202. 203 

Fossil 77 

Parianite 4, 132, 1:36,1-11 

Pavement. Asphaltic 16 f > 

Paving Blocks. Asphalt 211 

Wood, Analysis of 214 

Peat 77 

Petrolene 

70, 93, 98, 102, 106, 125, 149 ,155, 158, 

161, 162, 164, 166. 171 

Petroleum 76, 80 

Ether 102, 161, 187 

Soluble 105, 175 

Nitrogen in 125 

Oxygen in 43 

Pitch 208 

Residuum 78 

Spirit 157 

Sulphur in 40 

Pitch 66, 67, (59, 78, 160 

Ashes of 206 

Plaster of Paris 190 

Polymerization 68, 69, 74, 87 

Polycyclic Hydrocarbons 70 

Proximate Analysis of Solid Bitu- 
mens '. . . . 129 

Apparatus for 129 

Pyrobitumens 2, 6, 77, 78 

Pyroschists 48, 77 

Residual Pitches 6, 182, 193, 198 

Retene 9S. 99, 100, 101, 106 

Retine 98, 100, 101, 106 

Pock Asphalt Streets 286 

"Rule of Thumb" 295, 296 



INDEX OF SUBJECTS. 



321 



Page 

Russian Petroleum 43 

Sand 294 

Sandstone, Asphaltic 159 

Seyssel Rock 19, 78, 86, 159, 283 

Silicon, Organic Compounds of in Bi- 
tumen 120 

Sisquoc Asphalt 142 

Sludge Acid Tar 78, 88 

Society of Chemical Industry 218, 229 

Soxhlet Apparatus 140, 177, 193 

Solid Bitumens, Proximate Analysis 

of .129 

Soluble Alcohol 150 

Methyl 146 

Chloroform 138 

Hydrochloric Acid 139 

Petroleum Ether 137 

Turpentine 103. 138,142 

Specific Gravity 67. 71, 262 

Spectroscope 207, 211 

Street Mixtures 197, 212 

Successful Construction of 293 

Surfaces 107, 212, 213, 295 

Streets. Cracks in 292 

Styphnic Acid, from California Bitu- 
mens 109 

Sulphur 69, 70, 73, 108. 191, 228 

Determination of, Method of Ca- 

rius 110, 113, 117, 121 

Method of v. Konek 120, 122 

Eschka 118 

Garrett and Lomax 117 

Henriques 118 

Inner and Outer Crucible 114 

S. S. Sadtler 114 

Camp 122 

Engler 123 

Lidow 118 

Mabory 118, 122 

Parr's Calorimeter 120 

Peckham Ill, 112 



Page 
Sulphur- 

Per-oxide of Lead 109 

Per-oxide of Sodium 121 

In Pacific Coast Coals 110 

Summerland Oil 305 

Syrian Asphalt 153. 200 

Tar, of Various Kinds 66, 88 

The Chemistry of Solid Bitumens... 90 

The Origin of Bitumens 21 

Toluole 205 

Trap Rock 310 

Trinidad Asphaltum 158, 170 

Pitch 

4, 17, 73, 74. 90, 102, 111, 132, 152, 

153, 160, 161, 176, 188. 198, 200 

Alkaline Solution of .135 

Amido Compounds in 136 

Aqueous Solution of 134 

Gas in 133 

Humus in 135, 136 

Insoluble Residuum in 139 

Lake Water 133 

Mineral Matter in 141 

Pyrite in 140 

Turpentine 148, 162, 163, 193 

Soluble 143, 171 

Turrellite 8, 85, 144, 159, 170 

Analysis of 144, 145 

Uintahite 80 

Ultimate Analysis of Solid Bitumens. 107 
Val-de-Travers Asphalt. 55, 157, 159, 291 

Venturaite 40 

Warrenite 50, 51 

Water in Bitumen, Determination of 

137, 189 

Westphal Balance 180 

Wollastonite 236 

Wood Blocks 313 

Wood Tar Pitch 206 

Wurtzilite . 10 



INDEX OF NAMES. 



Page 

Abbott, N. B 3uu 

Albrecht, M 64, 65 

Allen, Alfred H 102, 142, 157, 174 

Angelin 30 

Atwood, Luther 39 

Atwood, Wm C9 

Barrande 30 

Berthelot 21 

Billings .'.'.'.'!.'.'.'!!! 30 

Bischof 28 35 

Blake, Prof. E. W 54 

Blount, B 229 233, ''35 243 

Bohm, Max 64, 65, 66, 71, 154 

Borhaave 5, 108 

Boussingault, J. B 

74, 90, 102, 13,1, 149, 154, 155, 172 

Bowen, H. C 27 6 

Carmichacl, H 210, 234 

Climont, J .'.269, 270 

Cooper, H. P 157 

Coquand 23 

Daubree, A .28 

Day, D. T . . 56 

Day, W. C 142 

Davies, E 157,205 

Dawson 30 

Delesse 28 

De Coulaine, M 282 283, 288, 297 



De Smedt, E. J..9S, 99, 100 



101, 156, 2? 
.159, 285, 290 



275, 282. 298 
3 



Delano, Wm. H 

Dow, A. W 

64, 65, 171, 193, 274 

Dubbs. J 

Durand-ClayS 198, 200, 209 

Dumas 94 

ETger, L 64, 65 

Ehrenberg 32 

Eirinis d'Erynys 19, 281 

Endemann, H 124, 143, 149, 172 

Engler, C -11, 122, 154 



Flachs, A 

Fogarty 

Friedlaender, S . 



154 

292 

. .122 



Garrett, F. E 117 

Goodale, Geo. 1 32 

Gregory 38 

Grittner, A C4, 65, 66 

Hall, James . . 37 

Harper, H. W 173 

Harrison, E. J 291 

Hauenschild 200 

Henriques 118 

Herschell, Sir J. F. W 32 

Hicks 30 

Hillebrand.221, 229, 230, 231, 233, 235. 243 

Hodgson. E. H 110, 112, 117 

Holde, D 63, 64, 65, 89, 122. 153, 203 

Holmes, J. G 266 

Humphrey, R. L 220, 234, 242 

Hunt, T. Sterry 

2, 6, 23, 35, 28, 31, 32, 33, 35, 46, 47 



Husler, J 

Jaccard 23 

Jacobsen, E 153 

Johnson, S. W 135 

Kayser, R ..130, 207 

Keller, H. F 142 

Kersch, B 64, 65 

Kieszling, R 122 

Kimball, J. B .18 

Kingzet t, C. T " 157 

Kohler, H 63, 67, 69, 73, 74, 7*5, '205 

Kovacs, J 64, 65, 66, 71, 89, 201 264 

Kramer, G 68, 202, 205, 270, 271 

Krepelka, V 64, 66, 69 

Le Bel gg 100, 149, 154 

Le Chatelier 240 

Leffmann, H 156 

Lenny 34 

Leslie, J. P 23 

Linton, L. A.. 104, 105, 138 154 172 186 

Locherer 155 

Lomax, E'. L 117 

Lunge, G.'. .4, 63, 64, 67, 69, 71/72, 75' 79 
Lyle, Sir Charles 32 

Mabery, C. F 

23, 27, 42, 44, 56, 68, 72 83, 87 88 

107, 125, 126, 262 

McCready 233 

Malenkovic 68, 74 

Malo, L 4, 75, 79, 10", 200, 284, 288 

Meade, R. K 233 

Meinecke, E 198, 199. 200, 200 

Mendeljeff 21, 24, !> 

Meunier 14< 

Moissan ....-.-., 24 

Muck 267 

Mulder 135 

Muntz 98, 100, 15 1 

Newberry, W. B 233, 240 

Newberry, S. B 221, 240 

Ohlmiiller 122 

Ormond. E 63 

Orton, Edward 23, 25, 59 



Parran, M 

Patern6 di Sessa Em .............. 64 

Paul 

Peckham, H. E .................. Ill, 

Peckham, S. F 

Pelouze and Cahours 

Phillips ............................ 56 

Pine, J. A. W 

Pratt, S. W 

Puvis ................................ 



55 
, 65 

30 
185 
I2r> 

42 
, 57 
160 

55 
282 



Redwood, B ........................... 43 

Reichenback ......................... 38 

Richardson, C ......................... 

6, 64, 65, 66, 69, 74, 75, 90, 102, 104. 131 
156, 177, 203, 221, 223, 225, 235, 242, 276 
294. 



323 



824 



IXPEX OP XAMES. 



Page 

Sadtler. S. P 

41. 101, 141. 143. ir.l, 156, 183 

Sadtler. S. S 114, 116 

Salathft. F 101, 109 

Sarnow, E 271 

Saussure * 

Shaffer. H. A 221 

Schenck-zu-Schweinsber*. E 268, 270 

Schmelck. 1 64, 65 

Schorlemmer 4: 

Secretan, M 281 

SSlligue 38 

Shimer, P. R 107. 114 

Sieplein. O. J 262 

Silliman, B.. Jr 42 

Smith, J. L 227, 253 



Page 

Sotet 201 

Spilker 202, 205 

Swain. (}. F 219 

Torrey. D 9l, 100, 106, 150 



240 

207 

92 

.120, 122 



Vicat 

Vogel, H. W. 
v. Humboldt 
v. Konek 



Wallace 103 

Warren, C. M 41. 72. 107, 109 

Warren and Storer 42 

Whinnery 103 

Wiley. H. W 136 

Wurtz, H 8, 44 



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Mortars and Concretes 

By MYRON S. FALK, Ph. D., 
Instructor in Civil Engineering, Columbia University. 

Cloth, 6 x 9 inches; 184 pages; illustrated; price, $2.50 net, postpaid. 

This book contains a very complete report of the results of tests made during the past 
fifteen years, and gives these results in tables and diagrams classified according to subjects. 
This is a reference book that should be in the library of every civil engineer. The contents 
include chapters on Chemical Properties of Cement, Physical Tests of Cement, General 
Physical Properties, Elastic Properties in General, Tensile Properties, Compressive Prop- 
erties, Flexural Properties, Report on Uniform Tests of Cement by the Special Committee 
of the American Society of Civil Engineers and Constitution of Cement. 

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The Myron C. Clark Publishing Co. 

355 Dearborn Street, CHICAGO 



ROCK EXCAVATION-METHODS AND COST. 

BY 

HALBERT P. GILLETTE, 

Editor ' 'Engineering-Contracting. ' ' 

This book covers the whole subject of rock excavation, 
whether in excavations for structures or in quarries. Tunneling, 
shaft sinking and quarrying and crushing are considered in par- 
ticular detail. It is a practical book for practical rock men. 
One superintendent who purchased this book writes that he has 
cut the cost of his drilling and blasting practically in half since 
he received the book and applied the methods given by Mr. Gil- 
lette. "Rock Excavation" has chapters describing: 

Rocks and Their Properties Methods and Cost of Hand Drilling 
Machine Drills and Their Use Steam and Compressed Air Plants The 
Cost of Machine Drilling Cost of Diamond Drilling Explosives Charg- 
ing and Firing Methods of Blasting Cost of Loading and Transporting 
Rock Quarrying Stone Open Cut Excavation Methods and Cost on 
the Chicago Drainage Canal Cost of Trenches and Subways Subaque- 
ous Excavation Cost of Railway Tunnels Cost of Drifting, Shaft Sink- 
ing and Stoping. 

Cloth, 5^x7 inches, 384 pages, 56 figures and illustrations; $3. 00 net, 
postpaid. 

EARTHWORK AND ITS COST. 

BY 

HALBERT P. GILLETTE, 

Editor "Engineering-Contracting" 

A book that should be in the hands of every man who is in 
charge of "moving dirt," whether with pick and shovel, plow 
and scraper, steam shovel and dredge, or any other tool for dig- 
ging and conveying earth. 

Cloth, 5x7^ inches, 260 pages, 50 figures and illustrations ; $2.00 net, 
postpaid. 

ECONOMICS OF ROAD CONSTRUCTION. 

BY 

HALBERT P. GILLETTE, 

Editor ' ' Engineering-Contracting. ' ' 

This book is the only book on road construction that goes 
into the detailed cost of construction. The methods and cost 
of construction given are drawn from the author's own expe- 
rience, both as an engineer in charge of road work and as a con- 
tractor for constructing many miles of roads of all kinds. 
Cloth, 184 pages, illustrated ; price $1.00 net, postpaid. 



THE MYRON C. CLARK PUBLISHING COMPANY 
355 Dearborn Street, CHICAGO 



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399016 




UNIVERSITY OF CALIFORNIA LIBRARY 



